[PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das]

During runtime-suspend of ufs host, the scsi devices are
already suspended and so are the queues associated with them.
But the ufs host sends SSU to wlun during its runtime-suspend.
During the process blk_queue_enter checks if the queue is not in
suspended state. If so, it waits for the queue to resume, and never
comes out of it.
The commit
(d55d15a33: scsi: block: Do not accept any requests while suspended)
adds the check if the queue is in suspended state in blk_queue_enter().

Call trace:
 __switch_to+0x174/0x2c4
 __schedule+0x478/0x764
 schedule+0x9c/0xe0
 blk_queue_enter+0x158/0x228
 blk_mq_alloc_request+0x40/0xa4
 blk_get_request+0x2c/0x70
 __scsi_execute+0x60/0x1c4
 ufshcd_set_dev_pwr_mode+0x124/0x1e4
 ufshcd_suspend+0x208/0x83c
 ufshcd_runtime_suspend+0x40/0x154
 ufshcd_pltfrm_runtime_suspend+0x14/0x20
 pm_generic_runtime_suspend+0x28/0x3c
 __rpm_callback+0x80/0x2a4
 rpm_suspend+0x308/0x614
 rpm_idle+0x158/0x228
 pm_runtime_work+0x84/0xac
 process_one_work+0x1f0/0x470
 worker_thread+0x26c/0x4c8
 kthread+0x13c/0x320
 ret_from_fork+0x10/0x18

Fix this by registering ufs device wlun as a scsi driver and
registering it for block runtime-pm. Also make this as a
supplier for all other luns. That way, this device wlun
suspends after all the consumers and resumes after
hba resumes.

Co-developed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
 drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
 drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
 drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
 drivers/scsi/ufs/ufs-exynos.c      |   2 +
 drivers/scsi/ufs/ufs-hisi.c        |   2 +
 drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
 drivers/scsi/ufs/ufs-qcom.c        |   2 +
 drivers/scsi/ufs/ufs_bsg.c         |   6 +-
 drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
 drivers/scsi/ufs/ufshcd.c          | 622 ++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.h          |   6 +
 include/trace/events/ufs.h         |  20 ++
 13 files changed, 491 insertions(+), 225 deletions(-)

diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
index 149391f..3e70c23 100644
--- a/drivers/scsi/ufs/cdns-pltfrm.c
+++ b/drivers/scsi/ufs/cdns-pltfrm.c
@@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver cdns_ufs_pltfrm_driver = {
diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c
index 67a6a61..b01db12 100644
--- a/drivers/scsi/ufs/tc-dwc-g210-pci.c
+++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c
@@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
 	.runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
 	.runtime_resume  = tc_dwc_g210_pci_runtime_resume,
 	.runtime_idle    = tc_dwc_g210_pci_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {
diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
index dee98dc..06457d5 100644
--- a/drivers/scsi/ufs/ufs-debugfs.c
+++ b/drivers/scsi/ufs/ufs-debugfs.c
@@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
 	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
 }
 
-void __exit ufs_debugfs_exit(void)
+void ufs_debugfs_exit(void)
 {
 	debugfs_remove_recursive(ufs_debugfs_root);
 }
diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
index f35b39c..12c2730 100644
--- a/drivers/scsi/ufs/ufs-debugfs.h
+++ b/drivers/scsi/ufs/ufs-debugfs.h
@@ -9,7 +9,7 @@ struct ufs_hba;
 
 #ifdef CONFIG_DEBUG_FS
 void __init ufs_debugfs_init(void);
-void __exit ufs_debugfs_exit(void);
+void ufs_debugfs_exit(void);
 void ufs_debugfs_hba_init(struct ufs_hba *hba);
 void ufs_debugfs_hba_exit(struct ufs_hba *hba);
 #else
diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
index 267943a1..45c0b02 100644
--- a/drivers/scsi/ufs/ufs-exynos.c
+++ b/drivers/scsi/ufs/ufs-exynos.c
@@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver exynos_ufs_pltform = {
diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
index 0aa5813..d463b44 100644
--- a/drivers/scsi/ufs/ufs-hisi.c
+++ b/drivers/scsi/ufs/ufs-hisi.c
@@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_hisi_pltform = {
diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index c55202b..51c82e3 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
 	/* enable unipro clock gating feature */
 	ufs_mtk_cfg_unipro_cg(hba, true);
 
-	/* configure auto-hibern8 timer to 10ms */
-	if (ufshcd_is_auto_hibern8_supported(hba)) {
-		ufshcd_auto_hibern8_update(hba,
-			FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
-			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
-	}
+	/* will be configured during probe hba */
+	if (ufshcd_is_auto_hibern8_supported(hba))
+		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
+			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
 
 	ufs_mtk_setup_clk_gating(hba);
 
@@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_mtk_pltform = {
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index f97d7b0..9aa098a 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_qcom_pltform = {
diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
index 5b2bc1a..cbb5a90 100644
--- a/drivers/scsi/ufs/ufs_bsg.c
+++ b/drivers/scsi/ufs/ufs_bsg.c
@@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 
 	bsg_reply->reply_payload_rcv_len = 0;
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 
 	msgcode = bsg_request->msgcode;
 	switch (msgcode) {
@@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 		ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
 						&desc_len, desc_op);
 		if (ret) {
-			pm_runtime_put_sync(hba->dev);
+			scsi_autopm_put_device(hba->sdev_ufs_device);
 			goto out;
 		}
 
@@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 		break;
 	}
 
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 
 	if (!desc_buff)
 		goto out;
diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
index fadd566..5d4ffd2 100644
--- a/drivers/scsi/ufs/ufshcd-pci.c
+++ b/drivers/scsi/ufs/ufshcd-pci.c
@@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
 	return ufshcd_system_resume(dev_get_drvdata(dev));
 }
 
-/**
- * ufshcd_pci_poweroff - suspend-to-disk poweroff function
- * @dev: pointer to PCI device handle
- *
- * Returns 0 if successful
- * Returns non-zero otherwise
- */
-static int ufshcd_pci_poweroff(struct device *dev)
-{
-	struct ufs_hba *hba = dev_get_drvdata(dev);
-	int spm_lvl = hba->spm_lvl;
-	int ret;
-
-	/*
-	 * For poweroff we need to set the UFS device to PowerDown mode.
-	 * Force spm_lvl to ensure that.
-	 */
-	hba->spm_lvl = 5;
-	ret = ufshcd_system_suspend(hba);
-	hba->spm_lvl = spm_lvl;
-	return ret;
-}
-
 #endif /* !CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM
@@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 }
 
 static const struct dev_pm_ops ufshcd_pci_pm_ops = {
-#ifdef CONFIG_PM_SLEEP
-	.suspend	= ufshcd_pci_suspend,
-	.resume		= ufshcd_pci_resume,
-	.freeze		= ufshcd_pci_suspend,
-	.thaw		= ufshcd_pci_resume,
-	.poweroff	= ufshcd_pci_poweroff,
-	.restore	= ufshcd_pci_resume,
-#endif
 	SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
 			   ufshcd_pci_runtime_resume,
 			   ufshcd_pci_runtime_idle)
+	SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
+#ifdef CONFIG_PM_SLEEP
+	.prepare	= ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
+#endif
 };
 
 static const struct pci_device_id ufshcd_pci_tbl[] = {
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 45624c7..7106cb8 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -16,6 +16,7 @@
 #include <linux/bitfield.h>
 #include <linux/blk-pm.h>
 #include <linux/blkdev.h>
+#include <scsi/scsi_driver.h>
 #include "ufshcd.h"
 #include "ufs_quirks.h"
 #include "unipro.h"
@@ -78,6 +79,8 @@
 /* Polling time to wait for fDeviceInit */
 #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
 
+#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
 	({                                                              \
 		int _ret;                                               \
@@ -1556,7 +1559,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
 	if (value == hba->clk_scaling.is_enabled)
 		goto out;
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 	ufshcd_hold(hba, false);
 
 	hba->clk_scaling.is_enabled = value;
@@ -1572,7 +1575,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
 	}
 
 	ufshcd_release(hba);
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 out:
 	up(&hba->host_sem);
 	return err ? err : count;
@@ -2572,6 +2575,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
 	return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
 }
 
+static inline bool is_rpmb_wlun(struct scsi_device *sdev)
+{
+	return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
+}
+
+static inline bool is_device_wlun(struct scsi_device *sdev)
+{
+	return (sdev->lun ==
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
+}
+
 static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
 {
 	struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
@@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	if (update && !pm_runtime_suspended(hba->dev)) {
-		pm_runtime_get_sync(hba->dev);
+		scsi_autopm_get_device(hba->sdev_ufs_device);
 		ufshcd_hold(hba, false);
 		ufshcd_auto_hibern8_enable(hba);
 		ufshcd_release(hba);
-		pm_runtime_put(hba->dev);
+		scsi_autopm_put_device(hba->sdev_ufs_device);
 	}
 }
 EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
@@ -4808,6 +4822,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
 }
 
 /**
+ * ufshcd_setup_links - associate link b/w device wlun and other luns
+ * @sdev: pointer to SCSI device
+ * @hba: pointer to ufs hba
+ */
+static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
+{
+	struct device_link *link;
+
+	/*
+	 * device wlun is the supplier & rest of the luns are consumers
+	 * This ensures that device wlun suspends after all other luns.
+	 */
+	if (hba->sdev_ufs_device) {
+		link = device_link_add(&sdev->sdev_gendev,
+				       &hba->sdev_ufs_device->sdev_gendev,
+				       DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
+		if (!link) {
+			dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
+				dev_name(&hba->sdev_ufs_device->sdev_gendev));
+			return;
+		}
+		hba->luns_avail--;
+		/* Ignore REPORT_LUN wlun probing */
+		if (hba->luns_avail != 1) {
+			pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
+			pm_runtime_allow(&hba->sdev_ufs_device->sdev_gendev);
+			return;
+		}
+	} else {
+		/* device wlun is probed */
+		hba->luns_avail--;
+	}
+}
+
+/**
  * ufshcd_slave_alloc - handle initial SCSI device configurations
  * @sdev: pointer to SCSI device
  *
@@ -4838,6 +4887,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
 
 	ufshcd_get_lu_power_on_wp_status(hba, sdev);
 
+	ufshcd_setup_links(hba, sdev);
+
 	return 0;
 }
 
@@ -4869,8 +4920,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
 	if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
 		blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
-
-	if (ufshcd_is_rpm_autosuspend_allowed(hba))
+	/*
+	 * Block runtime-pm until all consumers are added.
+	 * Refer ufshcd_setup_links().
+	 */
+	if (is_device_wlun(sdev))
+		pm_runtime_forbid(&sdev->sdev_gendev);
+	else if (ufshcd_is_rpm_autosuspend_allowed(hba))
 		sdev->rpm_autosuspend = 1;
 
 	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
@@ -4985,15 +5041,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 			 * UFS device needs urgent BKOPs.
 			 */
 			if (!hba->pm_op_in_progress &&
-			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
-			    schedule_work(&hba->eeh_work)) {
-				/*
-				 * Prevent suspend once eeh_work is scheduled
-				 * to avoid deadlock between ufshcd_suspend
-				 * and exception event handler.
-				 */
-				pm_runtime_get_noresume(hba->dev);
-			}
+			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
+				/* Flushed in suspend */
+				schedule_work(&hba->eeh_work);
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
 			/* TODO: handle Reject UPIU Response */
@@ -5589,8 +5639,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
 	 * after a certain delay to recheck the threshold by next runtime
 	 * suspend.
 	 */
-	pm_runtime_get_sync(hba->dev);
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 }
 
 /**
@@ -5607,7 +5657,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 	u32 status = 0;
 	hba = container_of(work, struct ufs_hba, eeh_work);
 
-	pm_runtime_get_sync(hba->dev);
 	ufshcd_scsi_block_requests(hba);
 	err = ufshcd_get_ee_status(hba, &status);
 	if (err) {
@@ -5623,14 +5672,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 
 out:
 	ufshcd_scsi_unblock_requests(hba);
-	/*
-	 * pm_runtime_get_noresume is called while scheduling
-	 * eeh_work to avoid suspend racing with exception work.
-	 * Hence decrement usage counter using pm_runtime_put_noidle
-	 * to allow suspend on completion of exception event handler.
-	 */
-	pm_runtime_put_noidle(hba->dev);
-	pm_runtime_put(hba->dev);
 	return;
 }
 
@@ -5755,12 +5796,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
 
 static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
 {
-	pm_runtime_get_sync(hba->dev);
-	if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
+	scsi_autopm_get_device(hba->sdev_ufs_device);
+	if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
+	    hba->is_sys_suspended) {
 		enum ufs_pm_op pm_op;
 
 		/*
-		 * Don't assume anything of pm_runtime_get_sync(), if
+		 * Don't assume anything of resume, if
 		 * resume fails, irq and clocks can be OFF, and powers
 		 * can be OFF or in LPM.
 		 */
@@ -5789,7 +5831,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
 	ufshcd_release(hba);
 	if (ufshcd_is_clkscaling_supported(hba))
 		ufshcd_clk_scaling_suspend(hba, false);
-	pm_runtime_put(hba->dev);
+	pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
 }
 
 static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
@@ -5810,14 +5852,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
 
 	hba->is_sys_suspended = false;
 	/*
-	 * Set RPM status of hba device to RPM_ACTIVE,
+	 * Set RPM status of wlun device to RPM_ACTIVE,
 	 * this also clears its runtime error.
 	 */
-	ret = pm_runtime_set_active(hba->dev);
+	ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
 	/*
-	 * If hba device had runtime error, we also need to resume those
-	 * scsi devices under hba in case any of them has failed to be
-	 * resumed due to hba runtime resume failure. This is to unblock
+	 * If wlun device had runtime error, we also need to resume those
+	 * consumer scsi devices in case any of them has failed to be
+	 * resumed due to supplier runtime resume failure. This is to unblock
 	 * blk_queue_enter in case there are bios waiting inside it.
 	 */
 	if (!ret) {
@@ -7207,11 +7249,12 @@ static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
 
 static inline void ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
 {
+	int dly = is_device_wlun(sdev) ? 0:RPM_AUTOSUSPEND_DELAY_MS;
+
 	scsi_autopm_get_device(sdev);
 	blk_pm_runtime_init(sdev->request_queue, &sdev->sdev_gendev);
 	if (sdev->rpm_autosuspend)
-		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev,
-						 RPM_AUTOSUSPEND_DELAY_MS);
+		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev, dly);
 	scsi_autopm_put_device(sdev);
 }
 
@@ -7253,6 +7296,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
 		hba->sdev_ufs_device = NULL;
 		goto out;
 	}
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 	ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
 	scsi_device_put(hba->sdev_ufs_device);
 
@@ -7417,6 +7461,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 		goto out;
 	}
 
+	hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
+		desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
+
 	ufs_fixup_device_setup(hba);
 
 	ufshcd_wb_probe(hba, desc_buf);
@@ -7892,6 +7939,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 	ufshcd_set_ufs_dev_active(hba);
 	ufshcd_force_reset_auto_bkops(hba);
 	hba->wlun_dev_clr_ua = true;
+	hba->wlun_rpmb_clr_ua = true;
 
 	/* Gear up to HS gear if supported */
 	if (hba->max_pwr_info.is_valid) {
@@ -8475,7 +8523,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
 	 * handling context.
 	 */
 	hba->host->eh_noresume = 1;
-	ufshcd_clear_ua_wluns(hba);
+	if (hba->wlun_dev_clr_ua)
+		ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
 
 	cmd[4] = pwr_mode << 4;
 
@@ -8650,23 +8699,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
 		ufshcd_setup_hba_vreg(hba, true);
 }
 
-/**
- * ufshcd_suspend - helper function for suspend operations
- * @hba: per adapter instance
- * @pm_op: desired low power operation type
- *
- * This function will try to put the UFS device and link into low power
- * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
- * (System PM level).
- *
- * If this function is called during shutdown, it will make sure that
- * both UFS device and UFS link is powered off.
- *
- * NOTE: UFS device & link must be active before we enter in this function.
- *
- * Returns 0 for success and non-zero for failure
- */
-static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	int ret = 0;
 	int check_for_bkops;
@@ -8674,7 +8707,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	enum ufs_dev_pwr_mode req_dev_pwr_mode;
 	enum uic_link_state req_link_state;
 
-	hba->pm_op_in_progress = 1;
+	hba->pm_op_in_progress = true;
 	if (!ufshcd_is_shutdown_pm(pm_op)) {
 		pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
 			 hba->rpm_lvl : hba->spm_lvl;
@@ -8697,17 +8730,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 
 	if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
 			req_link_state == UIC_LINK_ACTIVE_STATE) {
-		goto disable_clks;
+		goto enable_scaling;
 	}
 
 	if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
 	    (req_link_state == hba->uic_link_state))
-		goto enable_gating;
+		goto enable_scaling;
 
 	/* UFS device & link must be active before we enter in this function */
 	if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
 		ret = -EINVAL;
-		goto enable_gating;
+		goto enable_scaling;
 	}
 
 	if (ufshcd_is_runtime_pm(pm_op)) {
@@ -8719,7 +8752,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 			 */
 			ret = ufshcd_urgent_bkops(hba);
 			if (ret)
-				goto enable_gating;
+				goto enable_scaling;
 		} else {
 			/* make sure that auto bkops is disabled */
 			ufshcd_disable_auto_bkops(hba);
@@ -8747,7 +8780,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		if (!hba->dev_info.b_rpm_dev_flush_capable) {
 			ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
 			if (ret)
-				goto enable_gating;
+				goto enable_scaling;
 		}
 	}
 
@@ -8760,7 +8793,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (ret)
 		goto set_dev_active;
 
-disable_clks:
 	/*
 	 * Call vendor specific suspend callback. As these callbacks may access
 	 * vendor specific host controller register space call them before the
@@ -8769,28 +8801,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	ret = ufshcd_vops_suspend(hba, pm_op);
 	if (ret)
 		goto set_link_active;
-	/*
-	 * Disable the host irq as host controller as there won't be any
-	 * host controller transaction expected till resume.
-	 */
-	ufshcd_disable_irq(hba);
-
-	ufshcd_setup_clocks(hba, false);
-
-	if (ufshcd_is_clkgating_allowed(hba)) {
-		hba->clk_gating.state = CLKS_OFF;
-		trace_ufshcd_clk_gating(dev_name(hba->dev),
-					hba->clk_gating.state);
-	}
-
-	ufshcd_vreg_set_lpm(hba);
-
-	/* Put the host controller in low power mode if possible */
-	ufshcd_hba_vreg_set_lpm(hba);
 	goto out;
 
 set_link_active:
-	ufshcd_vreg_set_hpm(hba);
 	/*
 	 * Device hardware reset is required to exit DeepSleep. Also, for
 	 * DeepSleep, the link is off so host reset and restore will be done
@@ -8812,57 +8825,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	}
 	if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
 		ufshcd_disable_auto_bkops(hba);
-enable_gating:
+enable_scaling:
 	if (ufshcd_is_clkscaling_supported(hba))
 		ufshcd_clk_scaling_suspend(hba, false);
 
-	hba->clk_gating.is_suspended = false;
 	hba->dev_info.b_rpm_dev_flush_capable = false;
-	ufshcd_clear_ua_wluns(hba);
-	ufshcd_release(hba);
 out:
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
 		schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
 			msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
 	}
 
-	hba->pm_op_in_progress = 0;
-
-	if (ret)
-		ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
+	if (ret) {
+		ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
+		hba->clk_gating.is_suspended = false;
+		ufshcd_release(hba);
+	}
+	hba->pm_op_in_progress = false;
 	return ret;
 }
 
-/**
- * ufshcd_resume - helper function for resume operations
- * @hba: per adapter instance
- * @pm_op: runtime PM or system PM
- *
- * This function basically brings the UFS device, UniPro link and controller
- * to active state.
- *
- * Returns 0 for success and non-zero for failure
- */
-static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	int ret;
-	enum uic_link_state old_link_state;
+	enum uic_link_state old_link_state = hba->uic_link_state;
 
-	hba->pm_op_in_progress = 1;
-	old_link_state = hba->uic_link_state;
-
-	ufshcd_hba_vreg_set_hpm(hba);
-	ret = ufshcd_vreg_set_hpm(hba);
-	if (ret)
-		goto out;
-
-	/* Make sure clocks are enabled before accessing controller */
-	ret = ufshcd_setup_clocks(hba, true);
-	if (ret)
-		goto disable_vreg;
-
-	/* enable the host irq as host controller would be active soon */
-	ufshcd_enable_irq(hba);
+	hba->pm_op_in_progress = true;
 
 	/*
 	 * Call vendor specific resume callback. As these callbacks may access
@@ -8871,7 +8859,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ret = ufshcd_vops_resume(hba, pm_op);
 	if (ret)
-		goto disable_irq_and_vops_clks;
+		goto out;
 
 	/* For DeepSleep, the only supported option is to have the link off */
 	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
@@ -8916,31 +8904,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		 */
 		ufshcd_urgent_bkops(hba);
 
-	hba->clk_gating.is_suspended = false;
-
-	if (ufshcd_is_clkscaling_supported(hba))
-		ufshcd_clk_scaling_suspend(hba, false);
-
-	/* Enable Auto-Hibernate if configured */
-	ufshcd_auto_hibern8_enable(hba);
+	if (hba->clk_scaling.is_allowed)
+		ufshcd_resume_clkscaling(hba);
 
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
 		hba->dev_info.b_rpm_dev_flush_capable = false;
 		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
 	}
 
-	ufshcd_clear_ua_wluns(hba);
-
-	/* Schedule clock gating in case of no access to UFS device yet */
-	ufshcd_release(hba);
-
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
 	goto out;
 
 set_old_link_state:
 	ufshcd_link_state_transition(hba, old_link_state, 0);
 vendor_suspend:
 	ufshcd_vops_suspend(hba, pm_op);
-disable_irq_and_vops_clks:
+out:
+	if (ret)
+		ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
+	hba->clk_gating.is_suspended = false;
+	ufshcd_release(hba);
+	hba->pm_op_in_progress = false;
+	return ret;
+}
+
+static int ufshcd_wl_runtime_suspend(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+	int ret;
+	ktime_t start = ktime_get();
+
+	hba = shost_priv(sdev->host);
+
+	ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
+	if (ret)
+		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+	trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
+		ktime_to_us(ktime_sub(ktime_get(), start)),
+		hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+	return ret;
+}
+
+static int ufshcd_wl_runtime_resume(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+	int ret = 0;
+	ktime_t start = ktime_get();
+
+	hba = shost_priv(sdev->host);
+
+	ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
+	if (ret)
+		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+	trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
+		ktime_to_us(ktime_sub(ktime_get(), start)),
+		hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ufshcd_wl_suspend(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+	int ret;
+	ktime_t start = ktime_get();
+
+	hba = shost_priv(sdev->host);
+	ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
+	if (ret)
+		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__,  ret);
+
+	trace_ufshcd_wl_suspend(dev_name(dev), ret,
+		ktime_to_us(ktime_sub(ktime_get(), start)),
+		hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+	return ret;
+}
+
+static int ufshcd_wl_resume(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+	int ret = 0;
+	ktime_t start = ktime_get();
+
+	if (pm_runtime_suspended(dev))
+		return 0;
+	hba = shost_priv(sdev->host);
+
+	ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
+	if (ret)
+		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+	trace_ufshcd_wl_resume(dev_name(dev), ret,
+		ktime_to_us(ktime_sub(ktime_get(), start)),
+		hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+	return ret;
+}
+#endif
+
+static void ufshcd_wl_shutdown(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+
+	hba = shost_priv(sdev->host);
+	/* Turn on everything while shutting down */
+	scsi_autopm_get_device(sdev);
+	scsi_device_quiesce(sdev);
+	shost_for_each_device(sdev, hba->host) {
+		if (sdev == hba->sdev_ufs_device)
+			continue;
+		scsi_device_quiesce(sdev);
+	}
+	__ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
+}
+
+/**
+ * ufshcd_suspend - helper function for suspend operations
+ * @hba: per adapter instance
+ *
+ * This function will put disable irqs, turn off clocks
+ * and set vreg and hba-vreg in lpm mode.
+ * Also check the description of __ufshcd_wl_suspend().
+ */
+static void ufshcd_suspend(struct ufs_hba *hba)
+{
+	hba->pm_op_in_progress = 1;
+
+	/*
+	 * Disable the host irq as host controller as there won't be any
+	 * host controller transaction expected till resume.
+	 */
 	ufshcd_disable_irq(hba);
 	ufshcd_setup_clocks(hba, false);
 	if (ufshcd_is_clkgating_allowed(hba)) {
@@ -8948,6 +9052,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
 	}
+
+	ufshcd_vreg_set_lpm(hba);
+	/* Put the host controller in low power mode if possible */
+	ufshcd_hba_vreg_set_lpm(hba);
+	hba->pm_op_in_progress = 0;
+}
+
+/**
+ * ufshcd_resume - helper function for resume operations
+ * @hba: per adapter instance
+ *
+ * This function basically turns on the regulators, clocks and
+ * irqs of the hba.
+ * Also check the description of __ufshcd_wl_resume().
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_resume(struct ufs_hba *hba)
+{
+	int ret;
+
+	hba->pm_op_in_progress = 1;
+
+	ufshcd_hba_vreg_set_hpm(hba);
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto out;
+
+	/* Make sure clocks are enabled before accessing controller */
+	ret = ufshcd_setup_clocks(hba, true);
+	if (ret)
+		goto disable_vreg;
+
+	/* enable the host irq as host controller would be active soon */
+	ufshcd_enable_irq(hba);
+	goto out;
+
 disable_vreg:
 	ufshcd_vreg_set_lpm(hba);
 out:
@@ -8962,6 +9103,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
  * @hba: per adapter instance
  *
  * Check the description of ufshcd_suspend() function for more details.
+ * Also check the description of __ufshcd_wl_suspend().
  *
  * Returns 0 for success and non-zero for failure
  */
@@ -8987,21 +9129,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
 	     !hba->dev_info.b_rpm_dev_flush_capable)
 		goto out;
 
-	if (pm_runtime_suspended(hba->dev)) {
-		/*
-		 * UFS device and/or UFS link low power states during runtime
-		 * suspend seems to be different than what is expected during
-		 * system suspend. Hence runtime resume the devic & link and
-		 * let the system suspend low power states to take effect.
-		 * TODO: If resume takes longer time, we might have optimize
-		 * it in future by not resuming everything if possible.
-		 */
-		ret = ufshcd_runtime_resume(hba);
-		if (ret)
-			goto out;
-	}
-
-	ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
+	ufshcd_suspend(hba);
 out:
 	trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
@@ -9023,7 +9151,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
 
 int ufshcd_system_resume(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)
@@ -9034,22 +9161,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
 		down(&hba->host_sem);
 	}
 
-	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
-		/*
-		 * Let the runtime resume take care of resuming
-		 * if runtime suspended.
-		 */
+	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
+		ufshcd_resume(hba);
 out:
-	trace_ufshcd_system_resume(dev_name(hba->dev), ret,
+	trace_ufshcd_system_resume(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	if (!ret)
-		hba->is_sys_suspended = false;
+
+	hba->is_sys_suspended = false;
 	up(&hba->host_sem);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_system_resume);
 
@@ -9058,12 +9181,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
  * @hba: per adapter instance
  *
  * Check the description of ufshcd_suspend() function for more details.
+ * Also check the description of __ufshcd_wl_suspend().
  *
  * Returns 0 for success and non-zero for failure
  */
 int ufshcd_runtime_suspend(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)
@@ -9072,12 +9195,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
 	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
+		ufshcd_suspend(hba);
 out:
-	trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
+	trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_runtime_suspend);
 
@@ -9085,26 +9208,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
  * ufshcd_runtime_resume - runtime resume routine
  * @hba: per adapter instance
  *
- * This function basically brings the UFS device, UniPro link and controller
+ * This function basically brings controller
  * to active state. Following operations are done in this function:
  *
  * 1. Turn on all the controller related clocks
- * 2. Bring the UniPro link out of Hibernate state
- * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
- *    to active state.
- * 4. If auto-bkops is enabled on the device, disable it.
- *
- * So following would be the possible power state after this function return
- * successfully:
- *	S1: UFS device in Active state with VCC rail ON
- *	    UniPro link in Active state
- *	    All the UFS/UniPro controller clocks are ON
- *
- * Returns 0 for success and non-zero for failure
+ * 2. Turn ON VCC rail
  */
 int ufshcd_runtime_resume(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)
@@ -9113,12 +9224,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
 	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
+		ufshcd_resume(hba);
 out:
-	trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
+	trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_runtime_resume);
 
@@ -9132,14 +9243,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
  * ufshcd_shutdown - shutdown routine
  * @hba: per adapter instance
  *
- * This function would power off both UFS device and UFS link.
+ * This function would turn off both UFS device and UFS hba
+ * regulators. It would also disable clocks.
  *
  * Returns 0 always to allow force shutdown even in case of errors.
  */
 int ufshcd_shutdown(struct ufs_hba *hba)
 {
-	int ret = 0;
-
 	down(&hba->host_sem);
 	hba->shutting_down = true;
 	up(&hba->host_sem);
@@ -9152,10 +9262,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
 
 	pm_runtime_get_sync(hba->dev);
 
-	ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
+	ufshcd_suspend(hba);
 out:
-	if (ret)
-		dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
 	hba->is_powered = false;
 	/* allow force shutdown even in case of errors */
 	return 0;
@@ -9477,15 +9585,163 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 }
 EXPORT_SYMBOL_GPL(ufshcd_init);
 
+void ufshcd_resume_complete(struct device *dev)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
+}
+EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
+
+int ufshcd_suspend_prepare(struct device *dev)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	/*
+	 * SCSI assumes that runtime-pm and system-pm for scsi drivers
+	 * are same. And it doesn't wake up the device for system-suspend
+	 * if it's runtime suspended. But ufs doesn't follow that.
+	 * The rpm-lvl and spm-lvl can be different in ufs.
+	 * Force it to honor system-suspend.
+	 */
+	scsi_autopm_get_device(hba->sdev_ufs_device);
+	/* Refer ufshcd_resume_complete() */
+	pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
+
+#ifdef CONFIG_PM_SLEEP
+static int ufshcd_wl_poweroff(struct device *dev)
+{
+	ufshcd_wl_shutdown(dev);
+	return 0;
+}
+#endif
+
+static int ufshcd_wl_probe(struct device *dev)
+{
+	return is_device_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
+}
+
+static int ufshcd_wl_remove(struct device *dev)
+{
+	pm_runtime_forbid(dev);
+	return 0;
+}
+
+static const struct dev_pm_ops ufshcd_wl_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend = ufshcd_wl_suspend,
+	.resume = ufshcd_wl_resume,
+	.freeze = ufshcd_wl_suspend,
+	.thaw = ufshcd_wl_resume,
+	.poweroff = ufshcd_wl_poweroff,
+	.restore = ufshcd_wl_resume,
+#endif
+	SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
+};
+
+/**
+ * ufs_dev_wlun_template - describes ufs device wlun
+ * ufs-device wlun - used to send pm commands
+ * All luns are consumers of ufs-device wlun.
+ *
+ * Currently, no sd driver is present for wluns.
+ * Hence the no specific pm operations are performed.
+ * With ufs design, SSU should be sent to ufs-device wlun.
+ * Hence register a scsi driver for ufs wluns only.
+ */
+static struct scsi_driver ufs_dev_wlun_template = {
+	.gendrv = {
+		.name = "ufs_device_wlun",
+		.owner = THIS_MODULE,
+		.probe = ufshcd_wl_probe,
+		.remove = ufshcd_wl_remove,
+		.pm = &ufshcd_wl_pm_ops,
+		.shutdown = ufshcd_wl_shutdown,
+	},
+};
+
+static int ufshcd_rpmb_probe(struct device *dev)
+{
+	return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
+}
+
+static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (!hba->wlun_rpmb_clr_ua)
+		return 0;
+	ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
+	if (!ret)
+		hba->wlun_rpmb_clr_ua = 0;
+	return ret;
+}
+
+static int ufshcd_rpmb_runtime_resume(struct device *dev)
+{
+	struct ufs_hba *hba = wlun_dev_to_hba(dev);
+
+	if (hba->sdev_rpmb)
+		return ufshcd_clear_rpmb_uac(hba);
+	return 0;
+}
+
+static int ufshcd_rpmb_resume(struct device *dev)
+{
+	struct ufs_hba *hba = wlun_dev_to_hba(dev);
+
+	if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
+		return ufshcd_clear_rpmb_uac(hba);
+	return 0;
+}
+
+static const struct dev_pm_ops ufs_rpmb_pm_ops = {
+	SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
+};
+
+/**
+ * Describes the ufs rpmb wlun.
+ * Used only to send uac.
+ */
+static struct scsi_driver ufs_rpmb_wlun_template = {
+	.gendrv = {
+		.name = "ufs_rpmb_wlun",
+		.owner = THIS_MODULE,
+		.probe = ufshcd_rpmb_probe,
+		.pm = &ufs_rpmb_pm_ops,
+	},
+};
+
 static int __init ufshcd_core_init(void)
 {
+	int ret;
+
 	ufs_debugfs_init();
+
+	ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
+	if (ret) {
+		ufs_debugfs_exit();
+		return ret;
+	}
+	ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
+	if (ret) {
+		ufs_debugfs_exit();
+		scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
+		return ret;
+	}
 	return 0;
 }
 
 static void __exit ufshcd_core_exit(void)
 {
 	ufs_debugfs_exit();
+	scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
+	scsi_unregister_driver(&ufs_rpmb_wlun_template.gendrv);
 }
 
 module_init(ufshcd_core_init);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index ee61f82..7841b2a 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -72,6 +72,8 @@ enum ufs_event_type {
 	UFS_EVT_LINK_STARTUP_FAIL,
 	UFS_EVT_RESUME_ERR,
 	UFS_EVT_SUSPEND_ERR,
+	UFS_EVT_WL_SUSP_ERR,
+	UFS_EVT_WL_RES_ERR,
 
 	/* abnormal events */
 	UFS_EVT_DEV_RESET,
@@ -804,6 +806,7 @@ struct ufs_hba {
 	struct list_head clk_list_head;
 
 	bool wlun_dev_clr_ua;
+	bool wlun_rpmb_clr_ua;
 
 	/* Number of requests aborts */
 	int req_abort_count;
@@ -841,6 +844,7 @@ struct ufs_hba {
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_root;
 #endif
+	u32 luns_avail;
 };
 
 /* Returns true if clocks can be gated. Otherwise false */
@@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 			     enum query_opcode desc_op);
 
 int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
+int ufshcd_suspend_prepare(struct device *dev);
+void ufshcd_resume_complete(struct device *dev);
 
 /* Wrapper functions for safely calling variant operations */
 static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
index e151477..d9d233b 100644
--- a/include/trace/events/ufs.h
+++ b/include/trace/events/ufs.h
@@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
 		      int dev_state, int link_state),
 	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
 
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
+	     TP_PROTO(const char *dev_name, int err, s64 usecs,
+		      int dev_state, int link_state),
+	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
+	     TP_PROTO(const char *dev_name, int err, s64 usecs,
+		      int dev_state, int link_state),
+	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
+	     TP_PROTO(const char *dev_name, int err, s64 usecs,
+		      int dev_state, int link_state),
+	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
+	     TP_PROTO(const char *dev_name, int err, s64 usecs,
+		      int dev_state, int link_state),
+	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
 TRACE_EVENT(ufshcd_command,
 	TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
 		 unsigned int tag, u32 doorbell, int transfer_len, u32 intr,
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH v12 2/2] ufs: sysfs: Resume the proper scsi device

[Asutosh Das]

Resumes the actual scsi device the unit descriptor of which
is being accessed instead of the hba alone.

Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufs-sysfs.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index acc54f5..3fc182b 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -245,9 +245,9 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
 		goto out;
 	}
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 	res = ufshcd_wb_ctrl(hba, wb_enable);
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 out:
 	up(&hba->host_sem);
 	return res < 0 ? res : count;
@@ -297,10 +297,10 @@ static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
 		goto out;
 	}
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 	ret = ufshcd_read_desc_param(hba, desc_id, desc_index,
 				param_offset, desc_buf, param_size);
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 	if (ret) {
 		ret = -EINVAL;
 		goto out;
@@ -678,7 +678,7 @@ static ssize_t _name##_show(struct device *dev,				\
 		up(&hba->host_sem);					\
 		return -ENOMEM;						\
 	}								\
-	pm_runtime_get_sync(hba->dev);					\
+	scsi_autopm_get_device(hba->sdev_ufs_device);			\
 	ret = ufshcd_query_descriptor_retry(hba,			\
 		UPIU_QUERY_OPCODE_READ_DESC, QUERY_DESC_IDN_DEVICE,	\
 		0, 0, desc_buf, &desc_len);				\
@@ -695,7 +695,7 @@ static ssize_t _name##_show(struct device *dev,				\
 		goto out;						\
 	ret = sysfs_emit(buf, "%s\n", desc_buf);			\
 out:									\
-	pm_runtime_put_sync(hba->dev);					\
+	scsi_autopm_put_device(hba->sdev_ufs_device);			\
 	kfree(desc_buf);						\
 	up(&hba->host_sem);						\
 	return ret;							\
@@ -744,10 +744,10 @@ static ssize_t _name##_show(struct device *dev,				\
 	}								\
 	if (ufshcd_is_wb_flags(QUERY_FLAG_IDN##_uname))			\
 		index = ufshcd_wb_get_query_index(hba);			\
-	pm_runtime_get_sync(hba->dev);					\
+	scsi_autopm_get_device(hba->sdev_ufs_device);			\
 	ret = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,	\
 		QUERY_FLAG_IDN##_uname, index, &flag);			\
-	pm_runtime_put_sync(hba->dev);					\
+	scsi_autopm_put_device(hba->sdev_ufs_device);			\
 	if (ret) {							\
 		ret = -EINVAL;						\
 		goto out;						\
@@ -813,10 +813,10 @@ static ssize_t _name##_show(struct device *dev,				\
 	}								\
 	if (ufshcd_is_wb_attrs(QUERY_ATTR_IDN##_uname))			\
 		index = ufshcd_wb_get_query_index(hba);			\
-	pm_runtime_get_sync(hba->dev);					\
+	scsi_autopm_get_device(hba->sdev_ufs_device);			\
 	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,	\
 		QUERY_ATTR_IDN##_uname, index, 0, &value);		\
-	pm_runtime_put_sync(hba->dev);					\
+	scsi_autopm_put_device(hba->sdev_ufs_device);			\
 	if (ret) {							\
 		ret = -EINVAL;						\
 		goto out;						\
@@ -899,11 +899,15 @@ static ssize_t _pname##_show(struct device *dev,			\
 	struct scsi_device *sdev = to_scsi_device(dev);			\
 	struct ufs_hba *hba = shost_priv(sdev->host);			\
 	u8 lun = ufshcd_scsi_to_upiu_lun(sdev->lun);			\
+	int ret;							\
 	if (!ufs_is_valid_unit_desc_lun(&hba->dev_info, lun,		\
 				_duname##_DESC_PARAM##_puname))		\
 		return -EINVAL;						\
-	return ufs_sysfs_read_desc_param(hba, QUERY_DESC_IDN_##_duname,	\
+	scsi_autopm_get_device(sdev);					\
+	ret = ufs_sysfs_read_desc_param(hba, QUERY_DESC_IDN_##_duname,	\
 		lun, _duname##_DESC_PARAM##_puname, buf, _size);	\
+	scsi_autopm_put_device(sdev);					\
+	return ret;							\
 }									\
 static DEVICE_ATTR_RO(_pname)
 
@@ -964,10 +968,10 @@ static ssize_t dyn_cap_needed_attribute_show(struct device *dev,
 		goto out;
 	}
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
 		QUERY_ATTR_IDN_DYN_CAP_NEEDED, lun, 0, &value);
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 	if (ret) {
 		ret = -EINVAL;
 		goto out;
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Bart Van Assche]

On 3/18/21 5:35 PM, Asutosh Das wrote:
> During runtime-suspend of ufs host, the scsi devices are
> already suspended and so are the queues associated with them.
> But the ufs host sends SSU to wlun during its runtime-suspend.
> During the process blk_queue_enter checks if the queue is not in
> suspended state. If so, it waits for the queue to resume, and never
> comes out of it.
> The commit
> (d55d15a33: scsi: block: Do not accept any requests while suspended)
> adds the check if the queue is in suspended state in blk_queue_enter().

What is the role of the WLUN during runtime suspend and why does a
command need to be sent to the WLUN during runtime suspend? Although it
is possible to derive this from the source code, please explain this in
the patch description.

What does the acronym SSU stand for? This doesn't seem like a commonly
used kernel acronym to me so please expand that acronym.

> Fix this by registering ufs device wlun as a scsi driver and
> registering it for block runtime-pm. Also make this as a
> supplier for all other luns. That way, this device wlun
> suspends after all the consumers and resumes after
> hba resumes.

That's an interesting solution.

> -void __exit ufs_debugfs_exit(void)
> +void ufs_debugfs_exit(void)

Is the above change related to the rest of this patch?

>  static struct platform_driver ufs_qcom_pltform = {
> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
> index 5b2bc1a..cbb5a90 100644
> --- a/drivers/scsi/ufs/ufs_bsg.c
> +++ b/drivers/scsi/ufs/ufs_bsg.c
> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>  
>  	bsg_reply->reply_payload_rcv_len = 0;
>  
> -	pm_runtime_get_sync(hba->dev);
> +	scsi_autopm_get_device(hba->sdev_ufs_device);

Can the pm_runtime_get_sync() to scsi_autopm_get_device() changes be
moved into a separate patch?

> +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
> +{
> +	return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
> +}

Has this patch been verified with checkpatch? Checkpatch should have
reported the following for the above code:

	return is not a function, parentheses are not required

> +static inline bool is_device_wlun(struct scsi_device *sdev)
> +{
> +	return (sdev->lun ==
> +		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
> +}

Same comment here.

>  		/*
> -		 * Don't assume anything of pm_runtime_get_sync(), if
> +		 * Don't assume anything of resume, if
>  		 * resume fails, irq and clocks can be OFF, and powers
>  		 * can be OFF or in LPM.
>  		 */

Please make better use of the horizontal space in the above comment by
making comment lines longer.

Thanks,

Bart.

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das (asd)]

On 3/18/2021 8:12 PM, Bart Van Assche wrote:
> On 3/18/21 5:35 PM, Asutosh Das wrote:
>> During runtime-suspend of ufs host, the scsi devices are
>> already suspended and so are the queues associated with them.
>> But the ufs host sends SSU to wlun during its runtime-suspend.
>> During the process blk_queue_enter checks if the queue is not in
>> suspended state. If so, it waits for the queue to resume, and never
>> comes out of it.
>> The commit
>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>> adds the check if the queue is in suspended state in blk_queue_enter().
> 
Hi Bart,
Thanks for the review comments.

> What is the role of the WLUN during runtime suspend and why does a
> command need to be sent to the WLUN during runtime suspend? Although it
> is possible to derive this from the source code, please explain this in
> the patch description.
> 
Ok. Will explain it in the next version.

> What does the acronym SSU stand for? This doesn't seem like a commonly
> used kernel acronym to me so please expand that acronym.
>
START STOP UNIT.
Anyway, I'll expand it in the next version.

>> Fix this by registering ufs device wlun as a scsi driver and
>> registering it for block runtime-pm. Also make this as a
>> supplier for all other luns. That way, this device wlun
>> suspends after all the consumers and resumes after
>> hba resumes.
> 
> That's an interesting solution.
> 
>> -void __exit ufs_debugfs_exit(void)
>> +void ufs_debugfs_exit(void)
> 
> Is the above change related to the rest of this patch?
> 
Yes, it's used to handle an error in ufshcd_core_init() function.

>>   static struct platform_driver ufs_qcom_pltform = {
>> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
>> index 5b2bc1a..cbb5a90 100644
>> --- a/drivers/scsi/ufs/ufs_bsg.c
>> +++ b/drivers/scsi/ufs/ufs_bsg.c
>> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>   
>>   	bsg_reply->reply_payload_rcv_len = 0;
>>   
>> -	pm_runtime_get_sync(hba->dev);
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
> 
> Can the pm_runtime_get_sync() to scsi_autopm_get_device() changes be
> moved into a separate patch?
>
I guess so. But then this patch would have issues when used independently.

>> +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
>> +{
>> +	return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
>> +}
> 
> Has this patch been verified with checkpatch? Checkpatch should have
> reported the following for the above code:
> 
> 	return is not a function, parentheses are not required
> 
Yes, it has been verified. But I didn't see any error reports.
Below is the o/p of checkpatch:

$ ./scripts/checkpatch.pl /tmp/up/ufs-pm-v12/*
------------------------------------------
/tmp/up/ufs-pm-v12/0000-cover-letter.patch
------------------------------------------
WARNING: Possible unwrapped commit description (prefer a maximum 75 
chars per line)
#107:
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project.

total: 0 errors, 1 warnings, 0 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
       mechanically convert to the typical style using --fix or 
--fix-inplace.

/tmp/up/ufs-pm-v12/0000-cover-letter.patch has style problems, please 
review.
-----------------------------------------------------------------------
/tmp/up/ufs-pm-v12/0001-scsi-ufs-Enable-power-management-for-wlun.patch
-----------------------------------------------------------------------
total: 0 errors, 0 warnings, 1180 lines checked

/tmp/up/ufs-pm-v12/0001-scsi-ufs-Enable-power-management-for-wlun.patch 
has no obvious style problems and is ready for submission.
---------------------------------------------------------------------
/tmp/up/ufs-pm-v12/0002-ufs-sysfs-Resume-the-proper-scsi-device.patch
---------------------------------------------------------------------
total: 0 errors, 0 warnings, 91 lines checked

/tmp/up/ufs-pm-v12/0002-ufs-sysfs-Resume-the-proper-scsi-device.patch 
has no obvious style problems and is ready for submission.

NOTE: If any of the errors are false positives, please report
       them to the maintainer, see CHECKPATCH in MAINTAINERS.


>> +static inline bool is_device_wlun(struct scsi_device *sdev)
>> +{
>> +	return (sdev->lun ==
>> +		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
>> +}
> 
> Same comment here.
> 
>>   		/*
>> -		 * Don't assume anything of pm_runtime_get_sync(), if
>> +		 * Don't assume anything of resume, if
>>   		 * resume fails, irq and clocks can be OFF, and powers
>>   		 * can be OFF or in LPM.
>>   		 */
> 
> Please make better use of the horizontal space in the above comment by
> making comment lines longer.
> 
Ok Sure.

> Thanks,
> 
> Bart.
> 

-asd

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Adrian Hunter]

On 19/03/21 2:35 am, Asutosh Das wrote:
> During runtime-suspend of ufs host, the scsi devices are
> already suspended and so are the queues associated with them.
> But the ufs host sends SSU to wlun during its runtime-suspend.
> During the process blk_queue_enter checks if the queue is not in
> suspended state. If so, it waits for the queue to resume, and never
> comes out of it.
> The commit
> (d55d15a33: scsi: block: Do not accept any requests while suspended)
> adds the check if the queue is in suspended state in blk_queue_enter().
> 
> Call trace:
>  __switch_to+0x174/0x2c4
>  __schedule+0x478/0x764
>  schedule+0x9c/0xe0
>  blk_queue_enter+0x158/0x228
>  blk_mq_alloc_request+0x40/0xa4
>  blk_get_request+0x2c/0x70
>  __scsi_execute+0x60/0x1c4
>  ufshcd_set_dev_pwr_mode+0x124/0x1e4
>  ufshcd_suspend+0x208/0x83c
>  ufshcd_runtime_suspend+0x40/0x154
>  ufshcd_pltfrm_runtime_suspend+0x14/0x20
>  pm_generic_runtime_suspend+0x28/0x3c
>  __rpm_callback+0x80/0x2a4
>  rpm_suspend+0x308/0x614
>  rpm_idle+0x158/0x228
>  pm_runtime_work+0x84/0xac
>  process_one_work+0x1f0/0x470
>  worker_thread+0x26c/0x4c8
>  kthread+0x13c/0x320
>  ret_from_fork+0x10/0x18
> 
> Fix this by registering ufs device wlun as a scsi driver and
> registering it for block runtime-pm. Also make this as a
> supplier for all other luns. That way, this device wlun
> suspends after all the consumers and resumes after
> hba resumes.
> 
> Co-developed-by: Can Guo <cang@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>

I have some more comments that may help straighten things out.

Also please look at ufs_debugfs_get_user_access() and
ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
sdev_ufs_device.

It would also be good if you could re-base on linux-next.

> ---
>  drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
>  drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
>  drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
>  drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
>  drivers/scsi/ufs/ufs-exynos.c      |   2 +
>  drivers/scsi/ufs/ufs-hisi.c        |   2 +
>  drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
>  drivers/scsi/ufs/ufs-qcom.c        |   2 +
>  drivers/scsi/ufs/ufs_bsg.c         |   6 +-
>  drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
>  drivers/scsi/ufs/ufshcd.c          | 622 ++++++++++++++++++++++++++-----------
>  drivers/scsi/ufs/ufshcd.h          |   6 +
>  include/trace/events/ufs.h         |  20 ++
>  13 files changed, 491 insertions(+), 225 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
> index 149391f..3e70c23 100644
> --- a/drivers/scsi/ufs/cdns-pltfrm.c
> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
> @@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
>  	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>  	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>  	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static struct platform_driver cdns_ufs_pltfrm_driver = {
> diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c
> index 67a6a61..b01db12 100644
> --- a/drivers/scsi/ufs/tc-dwc-g210-pci.c
> +++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c
> @@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
>  	.runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
>  	.runtime_resume  = tc_dwc_g210_pci_runtime_resume,
>  	.runtime_idle    = tc_dwc_g210_pci_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {
> diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
> index dee98dc..06457d5 100644
> --- a/drivers/scsi/ufs/ufs-debugfs.c
> +++ b/drivers/scsi/ufs/ufs-debugfs.c
> @@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
>  	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
>  }
>  
> -void __exit ufs_debugfs_exit(void)
> +void ufs_debugfs_exit(void)
>  {
>  	debugfs_remove_recursive(ufs_debugfs_root);
>  }
> diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
> index f35b39c..12c2730 100644
> --- a/drivers/scsi/ufs/ufs-debugfs.h
> +++ b/drivers/scsi/ufs/ufs-debugfs.h
> @@ -9,7 +9,7 @@ struct ufs_hba;
>  
>  #ifdef CONFIG_DEBUG_FS
>  void __init ufs_debugfs_init(void);
> -void __exit ufs_debugfs_exit(void);
> +void ufs_debugfs_exit(void);
>  void ufs_debugfs_hba_init(struct ufs_hba *hba);
>  void ufs_debugfs_hba_exit(struct ufs_hba *hba);
>  #else
> diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
> index 267943a1..45c0b02 100644
> --- a/drivers/scsi/ufs/ufs-exynos.c
> +++ b/drivers/scsi/ufs/ufs-exynos.c
> @@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
>  	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>  	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>  	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static struct platform_driver exynos_ufs_pltform = {
> diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
> index 0aa5813..d463b44 100644
> --- a/drivers/scsi/ufs/ufs-hisi.c
> +++ b/drivers/scsi/ufs/ufs-hisi.c
> @@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
>  	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>  	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>  	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static struct platform_driver ufs_hisi_pltform = {
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index c55202b..51c82e3 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
>  	/* enable unipro clock gating feature */
>  	ufs_mtk_cfg_unipro_cg(hba, true);
>  
> -	/* configure auto-hibern8 timer to 10ms */
> -	if (ufshcd_is_auto_hibern8_supported(hba)) {
> -		ufshcd_auto_hibern8_update(hba,
> -			FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
> -			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
> -	}
> +	/* will be configured during probe hba */
> +	if (ufshcd_is_auto_hibern8_supported(hba))
> +		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
> +			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
>  
>  	ufs_mtk_setup_clk_gating(hba);
>  
> @@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
>  	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>  	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>  	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static struct platform_driver ufs_mtk_pltform = {
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index f97d7b0..9aa098a 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
>  	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>  	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>  	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +	.prepare	 = ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
>  };
>  
>  static struct platform_driver ufs_qcom_pltform = {
> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
> index 5b2bc1a..cbb5a90 100644
> --- a/drivers/scsi/ufs/ufs_bsg.c
> +++ b/drivers/scsi/ufs/ufs_bsg.c
> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>  
>  	bsg_reply->reply_payload_rcv_len = 0;
>  
> -	pm_runtime_get_sync(hba->dev);
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>  
>  	msgcode = bsg_request->msgcode;
>  	switch (msgcode) {
> @@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>  		ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
>  						&desc_len, desc_op);
>  		if (ret) {
> -			pm_runtime_put_sync(hba->dev);
> +			scsi_autopm_put_device(hba->sdev_ufs_device);
>  			goto out;
>  		}
>  
> @@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>  		break;
>  	}
>  
> -	pm_runtime_put_sync(hba->dev);
> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>  
>  	if (!desc_buff)
>  		goto out;
> diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
> index fadd566..5d4ffd2 100644
> --- a/drivers/scsi/ufs/ufshcd-pci.c
> +++ b/drivers/scsi/ufs/ufshcd-pci.c
> @@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
>  	return ufshcd_system_resume(dev_get_drvdata(dev));
>  }
>  
> -/**
> - * ufshcd_pci_poweroff - suspend-to-disk poweroff function
> - * @dev: pointer to PCI device handle
> - *
> - * Returns 0 if successful
> - * Returns non-zero otherwise
> - */
> -static int ufshcd_pci_poweroff(struct device *dev)
> -{
> -	struct ufs_hba *hba = dev_get_drvdata(dev);
> -	int spm_lvl = hba->spm_lvl;
> -	int ret;
> -
> -	/*
> -	 * For poweroff we need to set the UFS device to PowerDown mode.
> -	 * Force spm_lvl to ensure that.
> -	 */
> -	hba->spm_lvl = 5;
> -	ret = ufshcd_system_suspend(hba);
> -	hba->spm_lvl = spm_lvl;
> -	return ret;
> -}
> -
>  #endif /* !CONFIG_PM_SLEEP */
>  
>  #ifdef CONFIG_PM
> @@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  }
>  
>  static const struct dev_pm_ops ufshcd_pci_pm_ops = {
> -#ifdef CONFIG_PM_SLEEP
> -	.suspend	= ufshcd_pci_suspend,
> -	.resume		= ufshcd_pci_resume,
> -	.freeze		= ufshcd_pci_suspend,
> -	.thaw		= ufshcd_pci_resume,
> -	.poweroff	= ufshcd_pci_poweroff,
> -	.restore	= ufshcd_pci_resume,
> -#endif
>  	SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
>  			   ufshcd_pci_runtime_resume,
>  			   ufshcd_pci_runtime_idle)
> +	SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
> +#ifdef CONFIG_PM_SLEEP
> +	.prepare	= ufshcd_suspend_prepare,
> +	.complete	= ufshcd_resume_complete,
> +#endif
>  };
>  
>  static const struct pci_device_id ufshcd_pci_tbl[] = {
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 45624c7..7106cb8 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -16,6 +16,7 @@
>  #include <linux/bitfield.h>
>  #include <linux/blk-pm.h>
>  #include <linux/blkdev.h>
> +#include <scsi/scsi_driver.h>
>  #include "ufshcd.h"
>  #include "ufs_quirks.h"
>  #include "unipro.h"
> @@ -78,6 +79,8 @@
>  /* Polling time to wait for fDeviceInit */
>  #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
>  
> +#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
> +
>  #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
>  	({                                                              \
>  		int _ret;                                               \
> @@ -1556,7 +1559,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>  	if (value == hba->clk_scaling.is_enabled)
>  		goto out;
>  
> -	pm_runtime_get_sync(hba->dev);
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>  	ufshcd_hold(hba, false);
>  
>  	hba->clk_scaling.is_enabled = value;
> @@ -1572,7 +1575,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>  	}
>  
>  	ufshcd_release(hba);
> -	pm_runtime_put_sync(hba->dev);
> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>  out:
>  	up(&hba->host_sem);
>  	return err ? err : count;
> @@ -2572,6 +2575,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
>  	return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
>  }
>  
> +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
> +{
> +	return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
> +}
> +
> +static inline bool is_device_wlun(struct scsi_device *sdev)
> +{
> +	return (sdev->lun ==
> +		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
> +}
> +
>  static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
>  {
>  	struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
> @@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
>  	spin_unlock_irqrestore(hba->host->host_lock, flags);
>  
>  	if (update && !pm_runtime_suspended(hba->dev)) {
> -		pm_runtime_get_sync(hba->dev);
> +		scsi_autopm_get_device(hba->sdev_ufs_device);
>  		ufshcd_hold(hba, false);
>  		ufshcd_auto_hibern8_enable(hba);
>  		ufshcd_release(hba);
> -		pm_runtime_put(hba->dev);
> +		scsi_autopm_put_device(hba->sdev_ufs_device);
>  	}
>  }
>  EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
> @@ -4808,6 +4822,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
>  }
>  
>  /**
> + * ufshcd_setup_links - associate link b/w device wlun and other luns
> + * @sdev: pointer to SCSI device
> + * @hba: pointer to ufs hba
> + */
> +static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
> +{
> +	struct device_link *link;
> +
> +	/*
> +	 * device wlun is the supplier & rest of the luns are consumers
> +	 * This ensures that device wlun suspends after all other luns.
> +	 */
> +	if (hba->sdev_ufs_device) {
> +		link = device_link_add(&sdev->sdev_gendev,
> +				       &hba->sdev_ufs_device->sdev_gendev,
> +				       DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
> +		if (!link) {
> +			dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
> +				dev_name(&hba->sdev_ufs_device->sdev_gendev));
> +			return;
> +		}
> +		hba->luns_avail--;
> +		/* Ignore REPORT_LUN wlun probing */
> +		if (hba->luns_avail != 1) {

The condition here is the wrong way around. i.e. should be

		if (hba->luns_avail == 1) {

> +			pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);

If the usage_count is zero here, then we should let it suspend i.e. make this:

			pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);

Note this pairs with the pm_runtime_get_noresume() that needs to be added
to ufshcd_slave_configure.  Please see comments for ufshcd_slave_configure().


> +			pm_runtime_allow(&hba->sdev_ufs_device->sdev_gendev);

This pm_runtime_allow should not be here.  It should be in ufshcd_wl_probe().
Please see comments for ufshcd_wl_probe().

> +			return;
> +		}
> +	} else {
> +		/* device wlun is probed */
> +		hba->luns_avail--;
> +	}
> +}
> +
> +/**
>   * ufshcd_slave_alloc - handle initial SCSI device configurations
>   * @sdev: pointer to SCSI device
>   *
> @@ -4838,6 +4887,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
>  
>  	ufshcd_get_lu_power_on_wp_status(hba, sdev);
>  
> +	ufshcd_setup_links(hba, sdev);
> +
>  	return 0;
>  }
>  
> @@ -4869,8 +4920,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
>  	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
>  	if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
>  		blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
> -
> -	if (ufshcd_is_rpm_autosuspend_allowed(hba))
> +	/*
> +	 * Block runtime-pm until all consumers are added.
> +	 * Refer ufshcd_setup_links().
> +	 */
> +	if (is_device_wlun(sdev))
> +		pm_runtime_forbid(&sdev->sdev_gendev);

Since rpm_autosuspend is not being set for sdev_ufs_device, scsi_sysfs_add_sdev()
will pm_runtime_forbid() it anyway.  We should increase the usage_count instead
i.e.

		pm_runtime_get_noresume(&sdev->sdev_gendev);

> +	else if (ufshcd_is_rpm_autosuspend_allowed(hba))
>  		sdev->rpm_autosuspend = 1;
>  
>  	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
> @@ -4985,15 +5041,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>  			 * UFS device needs urgent BKOPs.
>  			 */
>  			if (!hba->pm_op_in_progress &&
> -			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
> -			    schedule_work(&hba->eeh_work)) {
> -				/*
> -				 * Prevent suspend once eeh_work is scheduled
> -				 * to avoid deadlock between ufshcd_suspend
> -				 * and exception event handler.
> -				 */
> -				pm_runtime_get_noresume(hba->dev);
> -			}
> +			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
> +				/* Flushed in suspend */
> +				schedule_work(&hba->eeh_work);
>  			break;
>  		case UPIU_TRANSACTION_REJECT_UPIU:
>  			/* TODO: handle Reject UPIU Response */
> @@ -5589,8 +5639,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
>  	 * after a certain delay to recheck the threshold by next runtime
>  	 * suspend.
>  	 */
> -	pm_runtime_get_sync(hba->dev);
> -	pm_runtime_put_sync(hba->dev);
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>  }
>  
>  /**
> @@ -5607,7 +5657,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>  	u32 status = 0;
>  	hba = container_of(work, struct ufs_hba, eeh_work);
>  
> -	pm_runtime_get_sync(hba->dev);
>  	ufshcd_scsi_block_requests(hba);
>  	err = ufshcd_get_ee_status(hba, &status);
>  	if (err) {
> @@ -5623,14 +5672,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>  
>  out:
>  	ufshcd_scsi_unblock_requests(hba);
> -	/*
> -	 * pm_runtime_get_noresume is called while scheduling
> -	 * eeh_work to avoid suspend racing with exception work.
> -	 * Hence decrement usage counter using pm_runtime_put_noidle
> -	 * to allow suspend on completion of exception event handler.
> -	 */
> -	pm_runtime_put_noidle(hba->dev);
> -	pm_runtime_put(hba->dev);
>  	return;
>  }
>  
> @@ -5755,12 +5796,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
>  
>  static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
>  {
> -	pm_runtime_get_sync(hba->dev);
> -	if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
> +	if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
> +	    hba->is_sys_suspended) {
>  		enum ufs_pm_op pm_op;
>  
>  		/*
> -		 * Don't assume anything of pm_runtime_get_sync(), if
> +		 * Don't assume anything of resume, if
>  		 * resume fails, irq and clocks can be OFF, and powers
>  		 * can be OFF or in LPM.
>  		 */
> @@ -5789,7 +5831,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>  	ufshcd_release(hba);
>  	if (ufshcd_is_clkscaling_supported(hba))
>  		ufshcd_clk_scaling_suspend(hba, false);
> -	pm_runtime_put(hba->dev);
> +	pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>  }
>  
>  static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
> @@ -5810,14 +5852,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
>  
>  	hba->is_sys_suspended = false;
>  	/*
> -	 * Set RPM status of hba device to RPM_ACTIVE,
> +	 * Set RPM status of wlun device to RPM_ACTIVE,
>  	 * this also clears its runtime error.
>  	 */
> -	ret = pm_runtime_set_active(hba->dev);
> +	ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
>  	/*
> -	 * If hba device had runtime error, we also need to resume those
> -	 * scsi devices under hba in case any of them has failed to be
> -	 * resumed due to hba runtime resume failure. This is to unblock
> +	 * If wlun device had runtime error, we also need to resume those
> +	 * consumer scsi devices in case any of them has failed to be
> +	 * resumed due to supplier runtime resume failure. This is to unblock
>  	 * blk_queue_enter in case there are bios waiting inside it.
>  	 */
>  	if (!ret) {
> @@ -7207,11 +7249,12 @@ static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
>  
>  static inline void ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
>  {
> +	int dly = is_device_wlun(sdev) ? 0:RPM_AUTOSUSPEND_DELAY_MS;
> +
>  	scsi_autopm_get_device(sdev);
>  	blk_pm_runtime_init(sdev->request_queue, &sdev->sdev_gendev);
>  	if (sdev->rpm_autosuspend)
> -		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev,
> -						 RPM_AUTOSUSPEND_DELAY_MS);
> +		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev, dly);
>  	scsi_autopm_put_device(sdev);
>  }
>  
> @@ -7253,6 +7296,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>  		hba->sdev_ufs_device = NULL;
>  		goto out;
>  	}
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>  	ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);

Let's drop both scsi_autopm_get_device() and ufshcd_blk_pm_runtime_init()
here and instead do things in ufshcd_wl_probe() - see comments for ufshcd_wl_probe()

>  	scsi_device_put(hba->sdev_ufs_device);
>  
> @@ -7417,6 +7461,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>  		goto out;
>  	}
>  
> +	hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
> +		desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
> +
>  	ufs_fixup_device_setup(hba);
>  
>  	ufshcd_wb_probe(hba, desc_buf);
> @@ -7892,6 +7939,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
>  	ufshcd_set_ufs_dev_active(hba);
>  	ufshcd_force_reset_auto_bkops(hba);
>  	hba->wlun_dev_clr_ua = true;
> +	hba->wlun_rpmb_clr_ua = true;
>  
>  	/* Gear up to HS gear if supported */
>  	if (hba->max_pwr_info.is_valid) {
> @@ -8475,7 +8523,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
>  	 * handling context.
>  	 */
>  	hba->host->eh_noresume = 1;
> -	ufshcd_clear_ua_wluns(hba);
> +	if (hba->wlun_dev_clr_ua)
> +		ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
>  
>  	cmd[4] = pwr_mode << 4;
>  
> @@ -8650,23 +8699,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
>  		ufshcd_setup_hba_vreg(hba, true);
>  }
>  
> -/**
> - * ufshcd_suspend - helper function for suspend operations
> - * @hba: per adapter instance
> - * @pm_op: desired low power operation type
> - *
> - * This function will try to put the UFS device and link into low power
> - * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
> - * (System PM level).
> - *
> - * If this function is called during shutdown, it will make sure that
> - * both UFS device and UFS link is powered off.
> - *
> - * NOTE: UFS device & link must be active before we enter in this function.
> - *
> - * Returns 0 for success and non-zero for failure
> - */
> -static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> +static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  {
>  	int ret = 0;
>  	int check_for_bkops;
> @@ -8674,7 +8707,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	enum ufs_dev_pwr_mode req_dev_pwr_mode;
>  	enum uic_link_state req_link_state;
>  
> -	hba->pm_op_in_progress = 1;
> +	hba->pm_op_in_progress = true;
>  	if (!ufshcd_is_shutdown_pm(pm_op)) {
>  		pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
>  			 hba->rpm_lvl : hba->spm_lvl;
> @@ -8697,17 +8730,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  
>  	if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
>  			req_link_state == UIC_LINK_ACTIVE_STATE) {
> -		goto disable_clks;
> +		goto enable_scaling;
>  	}
>  
>  	if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
>  	    (req_link_state == hba->uic_link_state))
> -		goto enable_gating;
> +		goto enable_scaling;
>  
>  	/* UFS device & link must be active before we enter in this function */
>  	if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
>  		ret = -EINVAL;
> -		goto enable_gating;
> +		goto enable_scaling;
>  	}
>  
>  	if (ufshcd_is_runtime_pm(pm_op)) {
> @@ -8719,7 +8752,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  			 */
>  			ret = ufshcd_urgent_bkops(hba);
>  			if (ret)
> -				goto enable_gating;
> +				goto enable_scaling;
>  		} else {
>  			/* make sure that auto bkops is disabled */
>  			ufshcd_disable_auto_bkops(hba);
> @@ -8747,7 +8780,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		if (!hba->dev_info.b_rpm_dev_flush_capable) {
>  			ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
>  			if (ret)
> -				goto enable_gating;
> +				goto enable_scaling;
>  		}
>  	}
>  
> @@ -8760,7 +8793,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
>  
> -disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may access
>  	 * vendor specific host controller register space call them before the
> @@ -8769,28 +8801,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ret = ufshcd_vops_suspend(hba, pm_op);
>  	if (ret)
>  		goto set_link_active;
> -	/*
> -	 * Disable the host irq as host controller as there won't be any
> -	 * host controller transaction expected till resume.
> -	 */
> -	ufshcd_disable_irq(hba);
> -
> -	ufshcd_setup_clocks(hba, false);
> -
> -	if (ufshcd_is_clkgating_allowed(hba)) {
> -		hba->clk_gating.state = CLKS_OFF;
> -		trace_ufshcd_clk_gating(dev_name(hba->dev),
> -					hba->clk_gating.state);
> -	}
> -
> -	ufshcd_vreg_set_lpm(hba);
> -
> -	/* Put the host controller in low power mode if possible */
> -	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
>  
>  set_link_active:
> -	ufshcd_vreg_set_hpm(hba);
>  	/*
>  	 * Device hardware reset is required to exit DeepSleep. Also, for
>  	 * DeepSleep, the link is off so host reset and restore will be done
> @@ -8812,57 +8825,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	}
>  	if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
>  		ufshcd_disable_auto_bkops(hba);
> -enable_gating:
> +enable_scaling:
>  	if (ufshcd_is_clkscaling_supported(hba))
>  		ufshcd_clk_scaling_suspend(hba, false);
>  
> -	hba->clk_gating.is_suspended = false;
>  	hba->dev_info.b_rpm_dev_flush_capable = false;
> -	ufshcd_clear_ua_wluns(hba);
> -	ufshcd_release(hba);
>  out:
>  	if (hba->dev_info.b_rpm_dev_flush_capable) {
>  		schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
>  			msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
>  	}
>  
> -	hba->pm_op_in_progress = 0;
> -
> -	if (ret)
> -		ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
> +	if (ret) {
> +		ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
> +		hba->clk_gating.is_suspended = false;
> +		ufshcd_release(hba);
> +	}
> +	hba->pm_op_in_progress = false;
>  	return ret;
>  }
>  
> -/**
> - * ufshcd_resume - helper function for resume operations
> - * @hba: per adapter instance
> - * @pm_op: runtime PM or system PM
> - *
> - * This function basically brings the UFS device, UniPro link and controller
> - * to active state.
> - *
> - * Returns 0 for success and non-zero for failure
> - */
> -static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> +static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  {
>  	int ret;
> -	enum uic_link_state old_link_state;
> +	enum uic_link_state old_link_state = hba->uic_link_state;
>  
> -	hba->pm_op_in_progress = 1;
> -	old_link_state = hba->uic_link_state;
> -
> -	ufshcd_hba_vreg_set_hpm(hba);
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto out;
> -
> -	/* Make sure clocks are enabled before accessing controller */
> -	ret = ufshcd_setup_clocks(hba, true);
> -	if (ret)
> -		goto disable_vreg;
> -
> -	/* enable the host irq as host controller would be active soon */
> -	ufshcd_enable_irq(hba);
> +	hba->pm_op_in_progress = true;
>  
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may access
> @@ -8871,7 +8859,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_irq_and_vops_clks;
> +		goto out;
>  
>  	/* For DeepSleep, the only supported option is to have the link off */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
> @@ -8916,31 +8904,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		 */
>  		ufshcd_urgent_bkops(hba);
>  
> -	hba->clk_gating.is_suspended = false;
> -
> -	if (ufshcd_is_clkscaling_supported(hba))
> -		ufshcd_clk_scaling_suspend(hba, false);
> -
> -	/* Enable Auto-Hibernate if configured */
> -	ufshcd_auto_hibern8_enable(hba);
> +	if (hba->clk_scaling.is_allowed)
> +		ufshcd_resume_clkscaling(hba);
>  
>  	if (hba->dev_info.b_rpm_dev_flush_capable) {
>  		hba->dev_info.b_rpm_dev_flush_capable = false;
>  		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
>  	}
>  
> -	ufshcd_clear_ua_wluns(hba);
> -
> -	/* Schedule clock gating in case of no access to UFS device yet */
> -	ufshcd_release(hba);
> -
> +	/* Enable Auto-Hibernate if configured */
> +	ufshcd_auto_hibern8_enable(hba);
>  	goto out;
>  
>  set_old_link_state:
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_irq_and_vops_clks:
> +out:
> +	if (ret)
> +		ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
> +	hba->clk_gating.is_suspended = false;
> +	ufshcd_release(hba);
> +	hba->pm_op_in_progress = false;
> +	return ret;
> +}
> +
> +static int ufshcd_wl_runtime_suspend(struct device *dev)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufs_hba *hba;
> +	int ret;
> +	ktime_t start = ktime_get();
> +
> +	hba = shost_priv(sdev->host);
> +
> +	ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
> +	if (ret)
> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
> +
> +	trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
> +		ktime_to_us(ktime_sub(ktime_get(), start)),
> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
> +
> +	return ret;
> +}
> +
> +static int ufshcd_wl_runtime_resume(struct device *dev)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufs_hba *hba;
> +	int ret = 0;
> +	ktime_t start = ktime_get();
> +
> +	hba = shost_priv(sdev->host);
> +
> +	ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
> +	if (ret)
> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
> +
> +	trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
> +		ktime_to_us(ktime_sub(ktime_get(), start)),
> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
> +
> +	return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ufshcd_wl_suspend(struct device *dev)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufs_hba *hba;
> +	int ret;
> +	ktime_t start = ktime_get();
> +
> +	hba = shost_priv(sdev->host);
> +	ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
> +	if (ret)
> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__,  ret);
> +
> +	trace_ufshcd_wl_suspend(dev_name(dev), ret,
> +		ktime_to_us(ktime_sub(ktime_get(), start)),
> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
> +
> +	return ret;
> +}
> +
> +static int ufshcd_wl_resume(struct device *dev)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufs_hba *hba;
> +	int ret = 0;
> +	ktime_t start = ktime_get();
> +
> +	if (pm_runtime_suspended(dev))
> +		return 0;
> +	hba = shost_priv(sdev->host);
> +
> +	ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
> +	if (ret)
> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
> +
> +	trace_ufshcd_wl_resume(dev_name(dev), ret,
> +		ktime_to_us(ktime_sub(ktime_get(), start)),
> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
> +
> +	return ret;
> +}
> +#endif
> +
> +static void ufshcd_wl_shutdown(struct device *dev)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufs_hba *hba;
> +
> +	hba = shost_priv(sdev->host);
> +	/* Turn on everything while shutting down */
> +	scsi_autopm_get_device(sdev);
> +	scsi_device_quiesce(sdev);
> +	shost_for_each_device(sdev, hba->host) {
> +		if (sdev == hba->sdev_ufs_device)
> +			continue;
> +		scsi_device_quiesce(sdev);
> +	}
> +	__ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
> +}
> +
> +/**
> + * ufshcd_suspend - helper function for suspend operations
> + * @hba: per adapter instance
> + *
> + * This function will put disable irqs, turn off clocks
> + * and set vreg and hba-vreg in lpm mode.
> + * Also check the description of __ufshcd_wl_suspend().
> + */
> +static void ufshcd_suspend(struct ufs_hba *hba)
> +{
> +	hba->pm_op_in_progress = 1;
> +
> +	/*
> +	 * Disable the host irq as host controller as there won't be any
> +	 * host controller transaction expected till resume.
> +	 */
>  	ufshcd_disable_irq(hba);
>  	ufshcd_setup_clocks(hba, false);
>  	if (ufshcd_is_clkgating_allowed(hba)) {
> @@ -8948,6 +9052,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +
> +	ufshcd_vreg_set_lpm(hba);
> +	/* Put the host controller in low power mode if possible */
> +	ufshcd_hba_vreg_set_lpm(hba);
> +	hba->pm_op_in_progress = 0;
> +}
> +
> +/**
> + * ufshcd_resume - helper function for resume operations
> + * @hba: per adapter instance
> + *
> + * This function basically turns on the regulators, clocks and
> + * irqs of the hba.
> + * Also check the description of __ufshcd_wl_resume().
> + *
> + * Returns 0 for success and non-zero for failure
> + */
> +static int ufshcd_resume(struct ufs_hba *hba)
> +{
> +	int ret;
> +
> +	hba->pm_op_in_progress = 1;
> +
> +	ufshcd_hba_vreg_set_hpm(hba);
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
> +	/* Make sure clocks are enabled before accessing controller */
> +	ret = ufshcd_setup_clocks(hba, true);
> +	if (ret)
> +		goto disable_vreg;
> +
> +	/* enable the host irq as host controller would be active soon */
> +	ufshcd_enable_irq(hba);
> +	goto out;
> +
>  disable_vreg:
>  	ufshcd_vreg_set_lpm(hba);
>  out:
> @@ -8962,6 +9103,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   * @hba: per adapter instance
>   *
>   * Check the description of ufshcd_suspend() function for more details.
> + * Also check the description of __ufshcd_wl_suspend().
>   *
>   * Returns 0 for success and non-zero for failure
>   */
> @@ -8987,21 +9129,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
>  	     !hba->dev_info.b_rpm_dev_flush_capable)
>  		goto out;
>  
> -	if (pm_runtime_suspended(hba->dev)) {
> -		/*
> -		 * UFS device and/or UFS link low power states during runtime
> -		 * suspend seems to be different than what is expected during
> -		 * system suspend. Hence runtime resume the devic & link and
> -		 * let the system suspend low power states to take effect.
> -		 * TODO: If resume takes longer time, we might have optimize
> -		 * it in future by not resuming everything if possible.
> -		 */
> -		ret = ufshcd_runtime_resume(hba);
> -		if (ret)
> -			goto out;
> -	}
> -
> -	ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
> +	ufshcd_suspend(hba);
>  out:
>  	trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
>  		ktime_to_us(ktime_sub(ktime_get(), start)),
> @@ -9023,7 +9151,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
>  
>  int ufshcd_system_resume(struct ufs_hba *hba)
>  {
> -	int ret = 0;
>  	ktime_t start = ktime_get();
>  
>  	if (!hba)
> @@ -9034,22 +9161,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
>  		down(&hba->host_sem);
>  	}
>  
> -	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
> -		/*
> -		 * Let the runtime resume take care of resuming
> -		 * if runtime suspended.
> -		 */
> +	if (!hba->is_powered)
>  		goto out;
>  	else
> -		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
> +		ufshcd_resume(hba);
>  out:
> -	trace_ufshcd_system_resume(dev_name(hba->dev), ret,
> +	trace_ufshcd_system_resume(dev_name(hba->dev), 0,
>  		ktime_to_us(ktime_sub(ktime_get(), start)),
>  		hba->curr_dev_pwr_mode, hba->uic_link_state);
> -	if (!ret)
> -		hba->is_sys_suspended = false;
> +
> +	hba->is_sys_suspended = false;
>  	up(&hba->host_sem);
> -	return ret;
> +	return 0;
>  }
>  EXPORT_SYMBOL(ufshcd_system_resume);
>  
> @@ -9058,12 +9181,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
>   * @hba: per adapter instance
>   *
>   * Check the description of ufshcd_suspend() function for more details.
> + * Also check the description of __ufshcd_wl_suspend().
>   *
>   * Returns 0 for success and non-zero for failure
>   */
>  int ufshcd_runtime_suspend(struct ufs_hba *hba)
>  {
> -	int ret = 0;
>  	ktime_t start = ktime_get();
>  
>  	if (!hba)
> @@ -9072,12 +9195,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
>  	if (!hba->is_powered)
>  		goto out;
>  	else
> -		ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
> +		ufshcd_suspend(hba);
>  out:
> -	trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
> +	trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
>  		ktime_to_us(ktime_sub(ktime_get(), start)),
>  		hba->curr_dev_pwr_mode, hba->uic_link_state);
> -	return ret;
> +	return 0;
>  }
>  EXPORT_SYMBOL(ufshcd_runtime_suspend);
>  
> @@ -9085,26 +9208,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
>   * ufshcd_runtime_resume - runtime resume routine
>   * @hba: per adapter instance
>   *
> - * This function basically brings the UFS device, UniPro link and controller
> + * This function basically brings controller
>   * to active state. Following operations are done in this function:
>   *
>   * 1. Turn on all the controller related clocks
> - * 2. Bring the UniPro link out of Hibernate state
> - * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
> - *    to active state.
> - * 4. If auto-bkops is enabled on the device, disable it.
> - *
> - * So following would be the possible power state after this function return
> - * successfully:
> - *	S1: UFS device in Active state with VCC rail ON
> - *	    UniPro link in Active state
> - *	    All the UFS/UniPro controller clocks are ON
> - *
> - * Returns 0 for success and non-zero for failure
> + * 2. Turn ON VCC rail
>   */
>  int ufshcd_runtime_resume(struct ufs_hba *hba)
>  {
> -	int ret = 0;
>  	ktime_t start = ktime_get();
>  
>  	if (!hba)
> @@ -9113,12 +9224,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
>  	if (!hba->is_powered)
>  		goto out;
>  	else
> -		ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
> +		ufshcd_resume(hba);
>  out:
> -	trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
> +	trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
>  		ktime_to_us(ktime_sub(ktime_get(), start)),
>  		hba->curr_dev_pwr_mode, hba->uic_link_state);
> -	return ret;
> +	return 0;
>  }
>  EXPORT_SYMBOL(ufshcd_runtime_resume);
>  
> @@ -9132,14 +9243,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
>   * ufshcd_shutdown - shutdown routine
>   * @hba: per adapter instance
>   *
> - * This function would power off both UFS device and UFS link.
> + * This function would turn off both UFS device and UFS hba
> + * regulators. It would also disable clocks.
>   *
>   * Returns 0 always to allow force shutdown even in case of errors.
>   */
>  int ufshcd_shutdown(struct ufs_hba *hba)
>  {
> -	int ret = 0;
> -
>  	down(&hba->host_sem);
>  	hba->shutting_down = true;
>  	up(&hba->host_sem);
> @@ -9152,10 +9262,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>  
>  	pm_runtime_get_sync(hba->dev);
>  
> -	ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
> +	ufshcd_suspend(hba);
>  out:
> -	if (ret)
> -		dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
>  	hba->is_powered = false;
>  	/* allow force shutdown even in case of errors */
>  	return 0;
> @@ -9477,15 +9585,163 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>  }
>  EXPORT_SYMBOL_GPL(ufshcd_init);
>  
> +void ufshcd_resume_complete(struct device *dev)
> +{
> +	struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +	pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
> +
> +int ufshcd_suspend_prepare(struct device *dev)
> +{
> +	struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +	/*
> +	 * SCSI assumes that runtime-pm and system-pm for scsi drivers
> +	 * are same. And it doesn't wake up the device for system-suspend
> +	 * if it's runtime suspended. But ufs doesn't follow that.
> +	 * The rpm-lvl and spm-lvl can be different in ufs.
> +	 * Force it to honor system-suspend.
> +	 */
> +	scsi_autopm_get_device(hba->sdev_ufs_device);
> +	/* Refer ufshcd_resume_complete() */
> +	pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
> +	scsi_autopm_put_device(hba->sdev_ufs_device);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ufshcd_wl_poweroff(struct device *dev)
> +{
> +	ufshcd_wl_shutdown(dev);
> +	return 0;
> +}
> +#endif
> +
> +static int ufshcd_wl_probe(struct device *dev)
> +{
> +	return is_device_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;

The "ufs_device_wlun" driver owns PM for sdev_ufs_device because it
provides the dev_pm_ops.  This is where the pm_runtime_allow() belongs
and it is symmetrical with the pm_runtime_forbid() in ufshcd_wl_remove().

	if (!is_device_wlun(to_scsi_device(dev)))
		return -ENODEV;
	blk_pm_runtime_init(dev);
	pm_runtime_set_autosuspend_delay(dev, 0);
	pm_runtime_allow(dev);

Note sdev_ufs_device will not runtime suspend here unless the
device links have been added and all consumers have suspended.
That is handled separately by the pm_runtime_get_noresume() in
ufshcd_slave_configure() and the pm_runtime_put() when luns_avail == 1
in ufshcd_setup_links().

> +}
> +
> +static int ufshcd_wl_remove(struct device *dev)
> +{
> +	pm_runtime_forbid(dev);
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops ufshcd_wl_pm_ops = {
> +#ifdef CONFIG_PM_SLEEP
> +	.suspend = ufshcd_wl_suspend,
> +	.resume = ufshcd_wl_resume,
> +	.freeze = ufshcd_wl_suspend,
> +	.thaw = ufshcd_wl_resume,
> +	.poweroff = ufshcd_wl_poweroff,
> +	.restore = ufshcd_wl_resume,
> +#endif
> +	SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
> +};
> +
> +/**
> + * ufs_dev_wlun_template - describes ufs device wlun
> + * ufs-device wlun - used to send pm commands
> + * All luns are consumers of ufs-device wlun.
> + *
> + * Currently, no sd driver is present for wluns.
> + * Hence the no specific pm operations are performed.
> + * With ufs design, SSU should be sent to ufs-device wlun.
> + * Hence register a scsi driver for ufs wluns only.
> + */
> +static struct scsi_driver ufs_dev_wlun_template = {
> +	.gendrv = {
> +		.name = "ufs_device_wlun",
> +		.owner = THIS_MODULE,
> +		.probe = ufshcd_wl_probe,
> +		.remove = ufshcd_wl_remove,
> +		.pm = &ufshcd_wl_pm_ops,
> +		.shutdown = ufshcd_wl_shutdown,
> +	},
> +};
> +
> +static int ufshcd_rpmb_probe(struct device *dev)
> +{
> +	return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
> +}
> +
> +static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
> +{
> +	int ret = 0;
> +
> +	if (!hba->wlun_rpmb_clr_ua)
> +		return 0;
> +	ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
> +	if (!ret)
> +		hba->wlun_rpmb_clr_ua = 0;
> +	return ret;
> +}
> +
> +static int ufshcd_rpmb_runtime_resume(struct device *dev)
> +{
> +	struct ufs_hba *hba = wlun_dev_to_hba(dev);
> +
> +	if (hba->sdev_rpmb)
> +		return ufshcd_clear_rpmb_uac(hba);
> +	return 0;
> +}
> +
> +static int ufshcd_rpmb_resume(struct device *dev)
> +{
> +	struct ufs_hba *hba = wlun_dev_to_hba(dev);
> +
> +	if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
> +		return ufshcd_clear_rpmb_uac(hba);
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops ufs_rpmb_pm_ops = {
> +	SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
> +};
> +
> +/**
> + * Describes the ufs rpmb wlun.
> + * Used only to send uac.
> + */
> +static struct scsi_driver ufs_rpmb_wlun_template = {
> +	.gendrv = {
> +		.name = "ufs_rpmb_wlun",
> +		.owner = THIS_MODULE,
> +		.probe = ufshcd_rpmb_probe,
> +		.pm = &ufs_rpmb_pm_ops,
> +	},
> +};
> +
>  static int __init ufshcd_core_init(void)
>  {
> +	int ret;
> +
>  	ufs_debugfs_init();
> +
> +	ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
> +	if (ret) {
> +		ufs_debugfs_exit();
> +		return ret;
> +	}
> +	ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
> +	if (ret) {
> +		ufs_debugfs_exit();
> +		scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
> +		return ret;
> +	}
>  	return 0;
>  }
>  
>  static void __exit ufshcd_core_exit(void)
>  {
>  	ufs_debugfs_exit();
> +	scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
> +	scsi_unregister_driver(&ufs_rpmb_wlun_template.gendrv);
>  }
>  
>  module_init(ufshcd_core_init);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index ee61f82..7841b2a 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -72,6 +72,8 @@ enum ufs_event_type {
>  	UFS_EVT_LINK_STARTUP_FAIL,
>  	UFS_EVT_RESUME_ERR,
>  	UFS_EVT_SUSPEND_ERR,
> +	UFS_EVT_WL_SUSP_ERR,
> +	UFS_EVT_WL_RES_ERR,
>  
>  	/* abnormal events */
>  	UFS_EVT_DEV_RESET,
> @@ -804,6 +806,7 @@ struct ufs_hba {
>  	struct list_head clk_list_head;
>  
>  	bool wlun_dev_clr_ua;
> +	bool wlun_rpmb_clr_ua;
>  
>  	/* Number of requests aborts */
>  	int req_abort_count;
> @@ -841,6 +844,7 @@ struct ufs_hba {
>  #ifdef CONFIG_DEBUG_FS
>  	struct dentry *debugfs_root;
>  #endif
> +	u32 luns_avail;
>  };
>  
>  /* Returns true if clocks can be gated. Otherwise false */
> @@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
>  			     enum query_opcode desc_op);
>  
>  int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
> +int ufshcd_suspend_prepare(struct device *dev);
> +void ufshcd_resume_complete(struct device *dev);
>  
>  /* Wrapper functions for safely calling variant operations */
>  static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
> diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
> index e151477..d9d233b 100644
> --- a/include/trace/events/ufs.h
> +++ b/include/trace/events/ufs.h
> @@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
>  		      int dev_state, int link_state),
>  	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>  
> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
> +		      int dev_state, int link_state),
> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
> +
> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
> +		      int dev_state, int link_state),
> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
> +
> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
> +		      int dev_state, int link_state),
> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
> +
> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
> +		      int dev_state, int link_state),
> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
> +
>  TRACE_EVENT(ufshcd_command,
>  	TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
>  		 unsigned int tag, u32 doorbell, int transfer_len, u32 intr,
> 

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Bart Van Assche]

On 3/19/21 10:47 AM, Adrian Hunter wrote:
> It would also be good if you could re-base on linux-next.

Hmm ... my understanding is that patches should be prepared on top of 
the for-next branch of the maintainer a patch is sent to, in this case 
the for-next branch of 
git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git.

Thanks,

Bart.

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das (asd)]

On 3/19/2021 10:47 AM, Adrian Hunter wrote:
> On 19/03/21 2:35 am, Asutosh Das wrote:
>> During runtime-suspend of ufs host, the scsi devices are
>> already suspended and so are the queues associated with them.
>> But the ufs host sends SSU to wlun during its runtime-suspend.
>> During the process blk_queue_enter checks if the queue is not in
>> suspended state. If so, it waits for the queue to resume, and never
>> comes out of it.
>> The commit
>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>> adds the check if the queue is in suspended state in blk_queue_enter().
>>
>> Call trace:
>>   __switch_to+0x174/0x2c4
>>   __schedule+0x478/0x764
>>   schedule+0x9c/0xe0
>>   blk_queue_enter+0x158/0x228
>>   blk_mq_alloc_request+0x40/0xa4
>>   blk_get_request+0x2c/0x70
>>   __scsi_execute+0x60/0x1c4
>>   ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>   ufshcd_suspend+0x208/0x83c
>>   ufshcd_runtime_suspend+0x40/0x154
>>   ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>   pm_generic_runtime_suspend+0x28/0x3c
>>   __rpm_callback+0x80/0x2a4
>>   rpm_suspend+0x308/0x614
>>   rpm_idle+0x158/0x228
>>   pm_runtime_work+0x84/0xac
>>   process_one_work+0x1f0/0x470
>>   worker_thread+0x26c/0x4c8
>>   kthread+0x13c/0x320
>>   ret_from_fork+0x10/0x18
>>
>> Fix this by registering ufs device wlun as a scsi driver and
>> registering it for block runtime-pm. Also make this as a
>> supplier for all other luns. That way, this device wlun
>> suspends after all the consumers and resumes after
>> hba resumes.
>>
>> Co-developed-by: Can Guo <cang@codeaurora.org>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
> 
> I have some more comments that may help straighten things out.
> 
> Also please look at ufs_debugfs_get_user_access() and
> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
> sdev_ufs_device.
> 
> It would also be good if you could re-base on linux-next.
> 

Hi Adrian
Thanks for the comments.

I agree moving the code to wlun probe and other changes.
But it looks to me that it may not fully solve the issue.

Please let me explain my understanding on this:

(Please refer to the logs in v10)
scsi_autopm_*() are invoked on a sdev.
pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.

For the device wlun:
	slave_configure():
		- doesn't set the rpm_autosuspend
		- pm_runtime_getnoresume()
	scsi_sysfs_add_sdev():
		- pm_runtime_forbid()
		- scsi_autopm_get_device()
		- device_add()
			- ufshcd_wl_probe()
		- scsi_autopm_put_device()

For all other scsi devices:
	slave_alloc():
		- ufshcd_setup_links()
Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
	slave_configure():
		- set rpm_autosuspend
	scsi_sysfs_add_sdev():
		- scsi_autopm_get_device()
		- device_add() -> schedules an async probe()
		- scsi_autopm_put_device() - (1)

Now the rpm_put_suppliers() can be invoked *after* 
pm_runtime_get_suppliers() of the async probe(), since both are running 
in different contexts.
In that case, the usage_count of supplier would be decremented until 
rpm_active of this link becomes 1.
Now the pm_runtime_get_suppliers() expects the link_active to be more 
than 1.
Now then, there comes a time, that when sd_probe() schedules a suspend, 
the supplier usage_count becomes 0 and the link_active becomes 1.
And the supplier suspends before the consumer.

So I was wondering, what'd make sure that the pm_runtime_get_suppliers() 
from driver_probe_device() is invoked after scsi_autopm_put_device() (1) 
finishes the rpm_put_suppliers().

Am not sure if I'm missing something in this.
Do you think, the current changes alone can fix the above issue?

-asd

>> ---
>>   drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
>>   drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
>>   drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
>>   drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
>>   drivers/scsi/ufs/ufs-exynos.c      |   2 +
>>   drivers/scsi/ufs/ufs-hisi.c        |   2 +
>>   drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
>>   drivers/scsi/ufs/ufs-qcom.c        |   2 +
>>   drivers/scsi/ufs/ufs_bsg.c         |   6 +-
>>   drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
>>   drivers/scsi/ufs/ufshcd.c          | 622 ++++++++++++++++++++++++++-----------
>>   drivers/scsi/ufs/ufshcd.h          |   6 +
>>   include/trace/events/ufs.h         |  20 ++
>>   13 files changed, 491 insertions(+), 225 deletions(-)
>>
>> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
>> index 149391f..3e70c23 100644
>> --- a/drivers/scsi/ufs/cdns-pltfrm.c
>> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
>> @@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
>>   	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>   	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>   	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static struct platform_driver cdns_ufs_pltfrm_driver = {
>> diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>> index 67a6a61..b01db12 100644
>> --- a/drivers/scsi/ufs/tc-dwc-g210-pci.c
>> +++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>> @@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
>>   	.runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
>>   	.runtime_resume  = tc_dwc_g210_pci_runtime_resume,
>>   	.runtime_idle    = tc_dwc_g210_pci_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {
>> diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
>> index dee98dc..06457d5 100644
>> --- a/drivers/scsi/ufs/ufs-debugfs.c
>> +++ b/drivers/scsi/ufs/ufs-debugfs.c
>> @@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
>>   	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
>>   }
>>   
>> -void __exit ufs_debugfs_exit(void)
>> +void ufs_debugfs_exit(void)
>>   {
>>   	debugfs_remove_recursive(ufs_debugfs_root);
>>   }
>> diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
>> index f35b39c..12c2730 100644
>> --- a/drivers/scsi/ufs/ufs-debugfs.h
>> +++ b/drivers/scsi/ufs/ufs-debugfs.h
>> @@ -9,7 +9,7 @@ struct ufs_hba;
>>   
>>   #ifdef CONFIG_DEBUG_FS
>>   void __init ufs_debugfs_init(void);
>> -void __exit ufs_debugfs_exit(void);
>> +void ufs_debugfs_exit(void);
>>   void ufs_debugfs_hba_init(struct ufs_hba *hba);
>>   void ufs_debugfs_hba_exit(struct ufs_hba *hba);
>>   #else
>> diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
>> index 267943a1..45c0b02 100644
>> --- a/drivers/scsi/ufs/ufs-exynos.c
>> +++ b/drivers/scsi/ufs/ufs-exynos.c
>> @@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
>>   	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>   	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>   	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static struct platform_driver exynos_ufs_pltform = {
>> diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
>> index 0aa5813..d463b44 100644
>> --- a/drivers/scsi/ufs/ufs-hisi.c
>> +++ b/drivers/scsi/ufs/ufs-hisi.c
>> @@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
>>   	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>   	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>   	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static struct platform_driver ufs_hisi_pltform = {
>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
>> index c55202b..51c82e3 100644
>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> @@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
>>   	/* enable unipro clock gating feature */
>>   	ufs_mtk_cfg_unipro_cg(hba, true);
>>   
>> -	/* configure auto-hibern8 timer to 10ms */
>> -	if (ufshcd_is_auto_hibern8_supported(hba)) {
>> -		ufshcd_auto_hibern8_update(hba,
>> -			FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>> -			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
>> -	}
>> +	/* will be configured during probe hba */
>> +	if (ufshcd_is_auto_hibern8_supported(hba))
>> +		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>> +			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
>>   
>>   	ufs_mtk_setup_clk_gating(hba);
>>   
>> @@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
>>   	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>   	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>   	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static struct platform_driver ufs_mtk_pltform = {
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index f97d7b0..9aa098a 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
>>   	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>   	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>   	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
>> +	.prepare	 = ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>>   };
>>   
>>   static struct platform_driver ufs_qcom_pltform = {
>> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
>> index 5b2bc1a..cbb5a90 100644
>> --- a/drivers/scsi/ufs/ufs_bsg.c
>> +++ b/drivers/scsi/ufs/ufs_bsg.c
>> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>   
>>   	bsg_reply->reply_payload_rcv_len = 0;
>>   
>> -	pm_runtime_get_sync(hba->dev);
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>>   
>>   	msgcode = bsg_request->msgcode;
>>   	switch (msgcode) {
>> @@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>   		ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
>>   						&desc_len, desc_op);
>>   		if (ret) {
>> -			pm_runtime_put_sync(hba->dev);
>> +			scsi_autopm_put_device(hba->sdev_ufs_device);
>>   			goto out;
>>   		}
>>   
>> @@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>   		break;
>>   	}
>>   
>> -	pm_runtime_put_sync(hba->dev);
>> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>>   
>>   	if (!desc_buff)
>>   		goto out;
>> diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
>> index fadd566..5d4ffd2 100644
>> --- a/drivers/scsi/ufs/ufshcd-pci.c
>> +++ b/drivers/scsi/ufs/ufshcd-pci.c
>> @@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
>>   	return ufshcd_system_resume(dev_get_drvdata(dev));
>>   }
>>   
>> -/**
>> - * ufshcd_pci_poweroff - suspend-to-disk poweroff function
>> - * @dev: pointer to PCI device handle
>> - *
>> - * Returns 0 if successful
>> - * Returns non-zero otherwise
>> - */
>> -static int ufshcd_pci_poweroff(struct device *dev)
>> -{
>> -	struct ufs_hba *hba = dev_get_drvdata(dev);
>> -	int spm_lvl = hba->spm_lvl;
>> -	int ret;
>> -
>> -	/*
>> -	 * For poweroff we need to set the UFS device to PowerDown mode.
>> -	 * Force spm_lvl to ensure that.
>> -	 */
>> -	hba->spm_lvl = 5;
>> -	ret = ufshcd_system_suspend(hba);
>> -	hba->spm_lvl = spm_lvl;
>> -	return ret;
>> -}
>> -
>>   #endif /* !CONFIG_PM_SLEEP */
>>   
>>   #ifdef CONFIG_PM
>> @@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>   }
>>   
>>   static const struct dev_pm_ops ufshcd_pci_pm_ops = {
>> -#ifdef CONFIG_PM_SLEEP
>> -	.suspend	= ufshcd_pci_suspend,
>> -	.resume		= ufshcd_pci_resume,
>> -	.freeze		= ufshcd_pci_suspend,
>> -	.thaw		= ufshcd_pci_resume,
>> -	.poweroff	= ufshcd_pci_poweroff,
>> -	.restore	= ufshcd_pci_resume,
>> -#endif
>>   	SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
>>   			   ufshcd_pci_runtime_resume,
>>   			   ufshcd_pci_runtime_idle)
>> +	SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
>> +#ifdef CONFIG_PM_SLEEP
>> +	.prepare	= ufshcd_suspend_prepare,
>> +	.complete	= ufshcd_resume_complete,
>> +#endif
>>   };
>>   
>>   static const struct pci_device_id ufshcd_pci_tbl[] = {
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 45624c7..7106cb8 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -16,6 +16,7 @@
>>   #include <linux/bitfield.h>
>>   #include <linux/blk-pm.h>
>>   #include <linux/blkdev.h>
>> +#include <scsi/scsi_driver.h>
>>   #include "ufshcd.h"
>>   #include "ufs_quirks.h"
>>   #include "unipro.h"
>> @@ -78,6 +79,8 @@
>>   /* Polling time to wait for fDeviceInit */
>>   #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
>>   
>> +#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
>> +
>>   #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
>>   	({                                                              \
>>   		int _ret;                                               \
>> @@ -1556,7 +1559,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>   	if (value == hba->clk_scaling.is_enabled)
>>   		goto out;
>>   
>> -	pm_runtime_get_sync(hba->dev);
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>>   	ufshcd_hold(hba, false);
>>   
>>   	hba->clk_scaling.is_enabled = value;
>> @@ -1572,7 +1575,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>   	}
>>   
>>   	ufshcd_release(hba);
>> -	pm_runtime_put_sync(hba->dev);
>> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>>   out:
>>   	up(&hba->host_sem);
>>   	return err ? err : count;
>> @@ -2572,6 +2575,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
>>   	return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
>>   }
>>   
>> +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
>> +{
>> +	return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
>> +}
>> +
>> +static inline bool is_device_wlun(struct scsi_device *sdev)
>> +{
>> +	return (sdev->lun ==
>> +		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
>> +}
>> +
>>   static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
>>   {
>>   	struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
>> @@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
>>   	spin_unlock_irqrestore(hba->host->host_lock, flags);
>>   
>>   	if (update && !pm_runtime_suspended(hba->dev)) {
>> -		pm_runtime_get_sync(hba->dev);
>> +		scsi_autopm_get_device(hba->sdev_ufs_device);
>>   		ufshcd_hold(hba, false);
>>   		ufshcd_auto_hibern8_enable(hba);
>>   		ufshcd_release(hba);
>> -		pm_runtime_put(hba->dev);
>> +		scsi_autopm_put_device(hba->sdev_ufs_device);
>>   	}
>>   }
>>   EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
>> @@ -4808,6 +4822,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
>>   }
>>   
>>   /**
>> + * ufshcd_setup_links - associate link b/w device wlun and other luns
>> + * @sdev: pointer to SCSI device
>> + * @hba: pointer to ufs hba
>> + */
>> +static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
>> +{
>> +	struct device_link *link;
>> +
>> +	/*
>> +	 * device wlun is the supplier & rest of the luns are consumers
>> +	 * This ensures that device wlun suspends after all other luns.
>> +	 */
>> +	if (hba->sdev_ufs_device) {
>> +		link = device_link_add(&sdev->sdev_gendev,
>> +				       &hba->sdev_ufs_device->sdev_gendev,
>> +				       DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
>> +		if (!link) {
>> +			dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
>> +				dev_name(&hba->sdev_ufs_device->sdev_gendev));
>> +			return;
>> +		}
>> +		hba->luns_avail--;
>> +		/* Ignore REPORT_LUN wlun probing */
>> +		if (hba->luns_avail != 1) {
> 
> The condition here is the wrong way around. i.e. should be
> 
> 		if (hba->luns_avail == 1) {
> 
>> +			pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
> 
> If the usage_count is zero here, then we should let it suspend i.e. make this:
> 
> 			pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
> 
> Note this pairs with the pm_runtime_get_noresume() that needs to be added
> to ufshcd_slave_configure.  Please see comments for ufshcd_slave_configure().
> 
> 
>> +			pm_runtime_allow(&hba->sdev_ufs_device->sdev_gendev);
> 
> This pm_runtime_allow should not be here.  It should be in ufshcd_wl_probe().
> Please see comments for ufshcd_wl_probe().
> 
>> +			return;
>> +		}
>> +	} else {
>> +		/* device wlun is probed */
>> +		hba->luns_avail--;
>> +	}
>> +}
>> +
>> +/**
>>    * ufshcd_slave_alloc - handle initial SCSI device configurations
>>    * @sdev: pointer to SCSI device
>>    *
>> @@ -4838,6 +4887,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
>>   
>>   	ufshcd_get_lu_power_on_wp_status(hba, sdev);
>>   
>> +	ufshcd_setup_links(hba, sdev);
>> +
>>   	return 0;
>>   }
>>   
>> @@ -4869,8 +4920,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
>>   	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
>>   	if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
>>   		blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
>> -
>> -	if (ufshcd_is_rpm_autosuspend_allowed(hba))
>> +	/*
>> +	 * Block runtime-pm until all consumers are added.
>> +	 * Refer ufshcd_setup_links().
>> +	 */
>> +	if (is_device_wlun(sdev))
>> +		pm_runtime_forbid(&sdev->sdev_gendev);
> 
> Since rpm_autosuspend is not being set for sdev_ufs_device, scsi_sysfs_add_sdev()
> will pm_runtime_forbid() it anyway.  We should increase the usage_count instead
> i.e.
> 
> 		pm_runtime_get_noresume(&sdev->sdev_gendev);
> 
>> +	else if (ufshcd_is_rpm_autosuspend_allowed(hba))
>>   		sdev->rpm_autosuspend = 1;
>>   
>>   	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
>> @@ -4985,15 +5041,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>>   			 * UFS device needs urgent BKOPs.
>>   			 */
>>   			if (!hba->pm_op_in_progress &&
>> -			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
>> -			    schedule_work(&hba->eeh_work)) {
>> -				/*
>> -				 * Prevent suspend once eeh_work is scheduled
>> -				 * to avoid deadlock between ufshcd_suspend
>> -				 * and exception event handler.
>> -				 */
>> -				pm_runtime_get_noresume(hba->dev);
>> -			}
>> +			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
>> +				/* Flushed in suspend */
>> +				schedule_work(&hba->eeh_work);
>>   			break;
>>   		case UPIU_TRANSACTION_REJECT_UPIU:
>>   			/* TODO: handle Reject UPIU Response */
>> @@ -5589,8 +5639,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
>>   	 * after a certain delay to recheck the threshold by next runtime
>>   	 * suspend.
>>   	 */
>> -	pm_runtime_get_sync(hba->dev);
>> -	pm_runtime_put_sync(hba->dev);
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>>   }
>>   
>>   /**
>> @@ -5607,7 +5657,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>   	u32 status = 0;
>>   	hba = container_of(work, struct ufs_hba, eeh_work);
>>   
>> -	pm_runtime_get_sync(hba->dev);
>>   	ufshcd_scsi_block_requests(hba);
>>   	err = ufshcd_get_ee_status(hba, &status);
>>   	if (err) {
>> @@ -5623,14 +5672,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>   
>>   out:
>>   	ufshcd_scsi_unblock_requests(hba);
>> -	/*
>> -	 * pm_runtime_get_noresume is called while scheduling
>> -	 * eeh_work to avoid suspend racing with exception work.
>> -	 * Hence decrement usage counter using pm_runtime_put_noidle
>> -	 * to allow suspend on completion of exception event handler.
>> -	 */
>> -	pm_runtime_put_noidle(hba->dev);
>> -	pm_runtime_put(hba->dev);
>>   	return;
>>   }
>>   
>> @@ -5755,12 +5796,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
>>   
>>   static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
>>   {
>> -	pm_runtime_get_sync(hba->dev);
>> -	if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>> +	if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
>> +	    hba->is_sys_suspended) {
>>   		enum ufs_pm_op pm_op;
>>   
>>   		/*
>> -		 * Don't assume anything of pm_runtime_get_sync(), if
>> +		 * Don't assume anything of resume, if
>>   		 * resume fails, irq and clocks can be OFF, and powers
>>   		 * can be OFF or in LPM.
>>   		 */
>> @@ -5789,7 +5831,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>>   	ufshcd_release(hba);
>>   	if (ufshcd_is_clkscaling_supported(hba))
>>   		ufshcd_clk_scaling_suspend(hba, false);
>> -	pm_runtime_put(hba->dev);
>> +	pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>   }
>>   
>>   static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
>> @@ -5810,14 +5852,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
>>   
>>   	hba->is_sys_suspended = false;
>>   	/*
>> -	 * Set RPM status of hba device to RPM_ACTIVE,
>> +	 * Set RPM status of wlun device to RPM_ACTIVE,
>>   	 * this also clears its runtime error.
>>   	 */
>> -	ret = pm_runtime_set_active(hba->dev);
>> +	ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
>>   	/*
>> -	 * If hba device had runtime error, we also need to resume those
>> -	 * scsi devices under hba in case any of them has failed to be
>> -	 * resumed due to hba runtime resume failure. This is to unblock
>> +	 * If wlun device had runtime error, we also need to resume those
>> +	 * consumer scsi devices in case any of them has failed to be
>> +	 * resumed due to supplier runtime resume failure. This is to unblock
>>   	 * blk_queue_enter in case there are bios waiting inside it.
>>   	 */
>>   	if (!ret) {
>> @@ -7207,11 +7249,12 @@ static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
>>   
>>   static inline void ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
>>   {
>> +	int dly = is_device_wlun(sdev) ? 0:RPM_AUTOSUSPEND_DELAY_MS;
>> +
>>   	scsi_autopm_get_device(sdev);
>>   	blk_pm_runtime_init(sdev->request_queue, &sdev->sdev_gendev);
>>   	if (sdev->rpm_autosuspend)
>> -		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev,
>> -						 RPM_AUTOSUSPEND_DELAY_MS);
>> +		pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev, dly);
>>   	scsi_autopm_put_device(sdev);
>>   }
>>   
>> @@ -7253,6 +7296,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>>   		hba->sdev_ufs_device = NULL;
>>   		goto out;
>>   	}
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>>   	ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
> 
> Let's drop both scsi_autopm_get_device() and ufshcd_blk_pm_runtime_init()
> here and instead do things in ufshcd_wl_probe() - see comments for ufshcd_wl_probe()
> 
>>   	scsi_device_put(hba->sdev_ufs_device);
>>   
>> @@ -7417,6 +7461,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>>   		goto out;
>>   	}
>>   
>> +	hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
>> +		desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
>> +
>>   	ufs_fixup_device_setup(hba);
>>   
>>   	ufshcd_wb_probe(hba, desc_buf);
>> @@ -7892,6 +7939,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
>>   	ufshcd_set_ufs_dev_active(hba);
>>   	ufshcd_force_reset_auto_bkops(hba);
>>   	hba->wlun_dev_clr_ua = true;
>> +	hba->wlun_rpmb_clr_ua = true;
>>   
>>   	/* Gear up to HS gear if supported */
>>   	if (hba->max_pwr_info.is_valid) {
>> @@ -8475,7 +8523,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
>>   	 * handling context.
>>   	 */
>>   	hba->host->eh_noresume = 1;
>> -	ufshcd_clear_ua_wluns(hba);
>> +	if (hba->wlun_dev_clr_ua)
>> +		ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
>>   
>>   	cmd[4] = pwr_mode << 4;
>>   
>> @@ -8650,23 +8699,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
>>   		ufshcd_setup_hba_vreg(hba, true);
>>   }
>>   
>> -/**
>> - * ufshcd_suspend - helper function for suspend operations
>> - * @hba: per adapter instance
>> - * @pm_op: desired low power operation type
>> - *
>> - * This function will try to put the UFS device and link into low power
>> - * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
>> - * (System PM level).
>> - *
>> - * If this function is called during shutdown, it will make sure that
>> - * both UFS device and UFS link is powered off.
>> - *
>> - * NOTE: UFS device & link must be active before we enter in this function.
>> - *
>> - * Returns 0 for success and non-zero for failure
>> - */
>> -static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> +static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   {
>>   	int ret = 0;
>>   	int check_for_bkops;
>> @@ -8674,7 +8707,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   	enum ufs_dev_pwr_mode req_dev_pwr_mode;
>>   	enum uic_link_state req_link_state;
>>   
>> -	hba->pm_op_in_progress = 1;
>> +	hba->pm_op_in_progress = true;
>>   	if (!ufshcd_is_shutdown_pm(pm_op)) {
>>   		pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
>>   			 hba->rpm_lvl : hba->spm_lvl;
>> @@ -8697,17 +8730,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   
>>   	if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
>>   			req_link_state == UIC_LINK_ACTIVE_STATE) {
>> -		goto disable_clks;
>> +		goto enable_scaling;
>>   	}
>>   
>>   	if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
>>   	    (req_link_state == hba->uic_link_state))
>> -		goto enable_gating;
>> +		goto enable_scaling;
>>   
>>   	/* UFS device & link must be active before we enter in this function */
>>   	if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
>>   		ret = -EINVAL;
>> -		goto enable_gating;
>> +		goto enable_scaling;
>>   	}
>>   
>>   	if (ufshcd_is_runtime_pm(pm_op)) {
>> @@ -8719,7 +8752,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   			 */
>>   			ret = ufshcd_urgent_bkops(hba);
>>   			if (ret)
>> -				goto enable_gating;
>> +				goto enable_scaling;
>>   		} else {
>>   			/* make sure that auto bkops is disabled */
>>   			ufshcd_disable_auto_bkops(hba);
>> @@ -8747,7 +8780,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   		if (!hba->dev_info.b_rpm_dev_flush_capable) {
>>   			ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
>>   			if (ret)
>> -				goto enable_gating;
>> +				goto enable_scaling;
>>   		}
>>   	}
>>   
>> @@ -8760,7 +8793,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   	if (ret)
>>   		goto set_dev_active;
>>   
>> -disable_clks:
>>   	/*
>>   	 * Call vendor specific suspend callback. As these callbacks may access
>>   	 * vendor specific host controller register space call them before the
>> @@ -8769,28 +8801,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   	ret = ufshcd_vops_suspend(hba, pm_op);
>>   	if (ret)
>>   		goto set_link_active;
>> -	/*
>> -	 * Disable the host irq as host controller as there won't be any
>> -	 * host controller transaction expected till resume.
>> -	 */
>> -	ufshcd_disable_irq(hba);
>> -
>> -	ufshcd_setup_clocks(hba, false);
>> -
>> -	if (ufshcd_is_clkgating_allowed(hba)) {
>> -		hba->clk_gating.state = CLKS_OFF;
>> -		trace_ufshcd_clk_gating(dev_name(hba->dev),
>> -					hba->clk_gating.state);
>> -	}
>> -
>> -	ufshcd_vreg_set_lpm(hba);
>> -
>> -	/* Put the host controller in low power mode if possible */
>> -	ufshcd_hba_vreg_set_lpm(hba);
>>   	goto out;
>>   
>>   set_link_active:
>> -	ufshcd_vreg_set_hpm(hba);
>>   	/*
>>   	 * Device hardware reset is required to exit DeepSleep. Also, for
>>   	 * DeepSleep, the link is off so host reset and restore will be done
>> @@ -8812,57 +8825,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   	}
>>   	if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
>>   		ufshcd_disable_auto_bkops(hba);
>> -enable_gating:
>> +enable_scaling:
>>   	if (ufshcd_is_clkscaling_supported(hba))
>>   		ufshcd_clk_scaling_suspend(hba, false);
>>   
>> -	hba->clk_gating.is_suspended = false;
>>   	hba->dev_info.b_rpm_dev_flush_capable = false;
>> -	ufshcd_clear_ua_wluns(hba);
>> -	ufshcd_release(hba);
>>   out:
>>   	if (hba->dev_info.b_rpm_dev_flush_capable) {
>>   		schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
>>   			msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
>>   	}
>>   
>> -	hba->pm_op_in_progress = 0;
>> -
>> -	if (ret)
>> -		ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
>> +	if (ret) {
>> +		ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
>> +		hba->clk_gating.is_suspended = false;
>> +		ufshcd_release(hba);
>> +	}
>> +	hba->pm_op_in_progress = false;
>>   	return ret;
>>   }
>>   
>> -/**
>> - * ufshcd_resume - helper function for resume operations
>> - * @hba: per adapter instance
>> - * @pm_op: runtime PM or system PM
>> - *
>> - * This function basically brings the UFS device, UniPro link and controller
>> - * to active state.
>> - *
>> - * Returns 0 for success and non-zero for failure
>> - */
>> -static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> +static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   {
>>   	int ret;
>> -	enum uic_link_state old_link_state;
>> +	enum uic_link_state old_link_state = hba->uic_link_state;
>>   
>> -	hba->pm_op_in_progress = 1;
>> -	old_link_state = hba->uic_link_state;
>> -
>> -	ufshcd_hba_vreg_set_hpm(hba);
>> -	ret = ufshcd_vreg_set_hpm(hba);
>> -	if (ret)
>> -		goto out;
>> -
>> -	/* Make sure clocks are enabled before accessing controller */
>> -	ret = ufshcd_setup_clocks(hba, true);
>> -	if (ret)
>> -		goto disable_vreg;
>> -
>> -	/* enable the host irq as host controller would be active soon */
>> -	ufshcd_enable_irq(hba);
>> +	hba->pm_op_in_progress = true;
>>   
>>   	/*
>>   	 * Call vendor specific resume callback. As these callbacks may access
>> @@ -8871,7 +8859,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   	 */
>>   	ret = ufshcd_vops_resume(hba, pm_op);
>>   	if (ret)
>> -		goto disable_irq_and_vops_clks;
>> +		goto out;
>>   
>>   	/* For DeepSleep, the only supported option is to have the link off */
>>   	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
>> @@ -8916,31 +8904,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   		 */
>>   		ufshcd_urgent_bkops(hba);
>>   
>> -	hba->clk_gating.is_suspended = false;
>> -
>> -	if (ufshcd_is_clkscaling_supported(hba))
>> -		ufshcd_clk_scaling_suspend(hba, false);
>> -
>> -	/* Enable Auto-Hibernate if configured */
>> -	ufshcd_auto_hibern8_enable(hba);
>> +	if (hba->clk_scaling.is_allowed)
>> +		ufshcd_resume_clkscaling(hba);
>>   
>>   	if (hba->dev_info.b_rpm_dev_flush_capable) {
>>   		hba->dev_info.b_rpm_dev_flush_capable = false;
>>   		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
>>   	}
>>   
>> -	ufshcd_clear_ua_wluns(hba);
>> -
>> -	/* Schedule clock gating in case of no access to UFS device yet */
>> -	ufshcd_release(hba);
>> -
>> +	/* Enable Auto-Hibernate if configured */
>> +	ufshcd_auto_hibern8_enable(hba);
>>   	goto out;
>>   
>>   set_old_link_state:
>>   	ufshcd_link_state_transition(hba, old_link_state, 0);
>>   vendor_suspend:
>>   	ufshcd_vops_suspend(hba, pm_op);
>> -disable_irq_and_vops_clks:
>> +out:
>> +	if (ret)
>> +		ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
>> +	hba->clk_gating.is_suspended = false;
>> +	ufshcd_release(hba);
>> +	hba->pm_op_in_progress = false;
>> +	return ret;
>> +}
>> +
>> +static int ufshcd_wl_runtime_suspend(struct device *dev)
>> +{
>> +	struct scsi_device *sdev = to_scsi_device(dev);
>> +	struct ufs_hba *hba;
>> +	int ret;
>> +	ktime_t start = ktime_get();
>> +
>> +	hba = shost_priv(sdev->host);
>> +
>> +	ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
>> +	if (ret)
>> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>> +
>> +	trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
>> +		ktime_to_us(ktime_sub(ktime_get(), start)),
>> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> +
>> +	return ret;
>> +}
>> +
>> +static int ufshcd_wl_runtime_resume(struct device *dev)
>> +{
>> +	struct scsi_device *sdev = to_scsi_device(dev);
>> +	struct ufs_hba *hba;
>> +	int ret = 0;
>> +	ktime_t start = ktime_get();
>> +
>> +	hba = shost_priv(sdev->host);
>> +
>> +	ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
>> +	if (ret)
>> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>> +
>> +	trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
>> +		ktime_to_us(ktime_sub(ktime_get(), start)),
>> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> +
>> +	return ret;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int ufshcd_wl_suspend(struct device *dev)
>> +{
>> +	struct scsi_device *sdev = to_scsi_device(dev);
>> +	struct ufs_hba *hba;
>> +	int ret;
>> +	ktime_t start = ktime_get();
>> +
>> +	hba = shost_priv(sdev->host);
>> +	ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
>> +	if (ret)
>> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__,  ret);
>> +
>> +	trace_ufshcd_wl_suspend(dev_name(dev), ret,
>> +		ktime_to_us(ktime_sub(ktime_get(), start)),
>> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> +
>> +	return ret;
>> +}
>> +
>> +static int ufshcd_wl_resume(struct device *dev)
>> +{
>> +	struct scsi_device *sdev = to_scsi_device(dev);
>> +	struct ufs_hba *hba;
>> +	int ret = 0;
>> +	ktime_t start = ktime_get();
>> +
>> +	if (pm_runtime_suspended(dev))
>> +		return 0;
>> +	hba = shost_priv(sdev->host);
>> +
>> +	ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
>> +	if (ret)
>> +		dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>> +
>> +	trace_ufshcd_wl_resume(dev_name(dev), ret,
>> +		ktime_to_us(ktime_sub(ktime_get(), start)),
>> +		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> +
>> +	return ret;
>> +}
>> +#endif
>> +
>> +static void ufshcd_wl_shutdown(struct device *dev)
>> +{
>> +	struct scsi_device *sdev = to_scsi_device(dev);
>> +	struct ufs_hba *hba;
>> +
>> +	hba = shost_priv(sdev->host);
>> +	/* Turn on everything while shutting down */
>> +	scsi_autopm_get_device(sdev);
>> +	scsi_device_quiesce(sdev);
>> +	shost_for_each_device(sdev, hba->host) {
>> +		if (sdev == hba->sdev_ufs_device)
>> +			continue;
>> +		scsi_device_quiesce(sdev);
>> +	}
>> +	__ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
>> +}
>> +
>> +/**
>> + * ufshcd_suspend - helper function for suspend operations
>> + * @hba: per adapter instance
>> + *
>> + * This function will put disable irqs, turn off clocks
>> + * and set vreg and hba-vreg in lpm mode.
>> + * Also check the description of __ufshcd_wl_suspend().
>> + */
>> +static void ufshcd_suspend(struct ufs_hba *hba)
>> +{
>> +	hba->pm_op_in_progress = 1;
>> +
>> +	/*
>> +	 * Disable the host irq as host controller as there won't be any
>> +	 * host controller transaction expected till resume.
>> +	 */
>>   	ufshcd_disable_irq(hba);
>>   	ufshcd_setup_clocks(hba, false);
>>   	if (ufshcd_is_clkgating_allowed(hba)) {
>> @@ -8948,6 +9052,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>   		trace_ufshcd_clk_gating(dev_name(hba->dev),
>>   					hba->clk_gating.state);
>>   	}
>> +
>> +	ufshcd_vreg_set_lpm(hba);
>> +	/* Put the host controller in low power mode if possible */
>> +	ufshcd_hba_vreg_set_lpm(hba);
>> +	hba->pm_op_in_progress = 0;
>> +}
>> +
>> +/**
>> + * ufshcd_resume - helper function for resume operations
>> + * @hba: per adapter instance
>> + *
>> + * This function basically turns on the regulators, clocks and
>> + * irqs of the hba.
>> + * Also check the description of __ufshcd_wl_resume().
>> + *
>> + * Returns 0 for success and non-zero for failure
>> + */
>> +static int ufshcd_resume(struct ufs_hba *hba)
>> +{
>> +	int ret;
>> +
>> +	hba->pm_op_in_progress = 1;
>> +
>> +	ufshcd_hba_vreg_set_hpm(hba);
>> +	ret = ufshcd_vreg_set_hpm(hba);
>> +	if (ret)
>> +		goto out;
>> +
>> +	/* Make sure clocks are enabled before accessing controller */
>> +	ret = ufshcd_setup_clocks(hba, true);
>> +	if (ret)
>> +		goto disable_vreg;
>> +
>> +	/* enable the host irq as host controller would be active soon */
>> +	ufshcd_enable_irq(hba);
>> +	goto out;
>> +
>>   disable_vreg:
>>   	ufshcd_vreg_set_lpm(hba);
>>   out:
>> @@ -8962,6 +9103,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>    * @hba: per adapter instance
>>    *
>>    * Check the description of ufshcd_suspend() function for more details.
>> + * Also check the description of __ufshcd_wl_suspend().
>>    *
>>    * Returns 0 for success and non-zero for failure
>>    */
>> @@ -8987,21 +9129,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
>>   	     !hba->dev_info.b_rpm_dev_flush_capable)
>>   		goto out;
>>   
>> -	if (pm_runtime_suspended(hba->dev)) {
>> -		/*
>> -		 * UFS device and/or UFS link low power states during runtime
>> -		 * suspend seems to be different than what is expected during
>> -		 * system suspend. Hence runtime resume the devic & link and
>> -		 * let the system suspend low power states to take effect.
>> -		 * TODO: If resume takes longer time, we might have optimize
>> -		 * it in future by not resuming everything if possible.
>> -		 */
>> -		ret = ufshcd_runtime_resume(hba);
>> -		if (ret)
>> -			goto out;
>> -	}
>> -
>> -	ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
>> +	ufshcd_suspend(hba);
>>   out:
>>   	trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
>>   		ktime_to_us(ktime_sub(ktime_get(), start)),
>> @@ -9023,7 +9151,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
>>   
>>   int ufshcd_system_resume(struct ufs_hba *hba)
>>   {
>> -	int ret = 0;
>>   	ktime_t start = ktime_get();
>>   
>>   	if (!hba)
>> @@ -9034,22 +9161,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
>>   		down(&hba->host_sem);
>>   	}
>>   
>> -	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
>> -		/*
>> -		 * Let the runtime resume take care of resuming
>> -		 * if runtime suspended.
>> -		 */
>> +	if (!hba->is_powered)
>>   		goto out;
>>   	else
>> -		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
>> +		ufshcd_resume(hba);
>>   out:
>> -	trace_ufshcd_system_resume(dev_name(hba->dev), ret,
>> +	trace_ufshcd_system_resume(dev_name(hba->dev), 0,
>>   		ktime_to_us(ktime_sub(ktime_get(), start)),
>>   		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> -	if (!ret)
>> -		hba->is_sys_suspended = false;
>> +
>> +	hba->is_sys_suspended = false;
>>   	up(&hba->host_sem);
>> -	return ret;
>> +	return 0;
>>   }
>>   EXPORT_SYMBOL(ufshcd_system_resume);
>>   
>> @@ -9058,12 +9181,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
>>    * @hba: per adapter instance
>>    *
>>    * Check the description of ufshcd_suspend() function for more details.
>> + * Also check the description of __ufshcd_wl_suspend().
>>    *
>>    * Returns 0 for success and non-zero for failure
>>    */
>>   int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>   {
>> -	int ret = 0;
>>   	ktime_t start = ktime_get();
>>   
>>   	if (!hba)
>> @@ -9072,12 +9195,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>   	if (!hba->is_powered)
>>   		goto out;
>>   	else
>> -		ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
>> +		ufshcd_suspend(hba);
>>   out:
>> -	trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
>> +	trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
>>   		ktime_to_us(ktime_sub(ktime_get(), start)),
>>   		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> -	return ret;
>> +	return 0;
>>   }
>>   EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>   
>> @@ -9085,26 +9208,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>    * ufshcd_runtime_resume - runtime resume routine
>>    * @hba: per adapter instance
>>    *
>> - * This function basically brings the UFS device, UniPro link and controller
>> + * This function basically brings controller
>>    * to active state. Following operations are done in this function:
>>    *
>>    * 1. Turn on all the controller related clocks
>> - * 2. Bring the UniPro link out of Hibernate state
>> - * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
>> - *    to active state.
>> - * 4. If auto-bkops is enabled on the device, disable it.
>> - *
>> - * So following would be the possible power state after this function return
>> - * successfully:
>> - *	S1: UFS device in Active state with VCC rail ON
>> - *	    UniPro link in Active state
>> - *	    All the UFS/UniPro controller clocks are ON
>> - *
>> - * Returns 0 for success and non-zero for failure
>> + * 2. Turn ON VCC rail
>>    */
>>   int ufshcd_runtime_resume(struct ufs_hba *hba)
>>   {
>> -	int ret = 0;
>>   	ktime_t start = ktime_get();
>>   
>>   	if (!hba)
>> @@ -9113,12 +9224,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
>>   	if (!hba->is_powered)
>>   		goto out;
>>   	else
>> -		ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
>> +		ufshcd_resume(hba);
>>   out:
>> -	trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
>> +	trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
>>   		ktime_to_us(ktime_sub(ktime_get(), start)),
>>   		hba->curr_dev_pwr_mode, hba->uic_link_state);
>> -	return ret;
>> +	return 0;
>>   }
>>   EXPORT_SYMBOL(ufshcd_runtime_resume);
>>   
>> @@ -9132,14 +9243,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
>>    * ufshcd_shutdown - shutdown routine
>>    * @hba: per adapter instance
>>    *
>> - * This function would power off both UFS device and UFS link.
>> + * This function would turn off both UFS device and UFS hba
>> + * regulators. It would also disable clocks.
>>    *
>>    * Returns 0 always to allow force shutdown even in case of errors.
>>    */
>>   int ufshcd_shutdown(struct ufs_hba *hba)
>>   {
>> -	int ret = 0;
>> -
>>   	down(&hba->host_sem);
>>   	hba->shutting_down = true;
>>   	up(&hba->host_sem);
>> @@ -9152,10 +9262,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>>   
>>   	pm_runtime_get_sync(hba->dev);
>>   
>> -	ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
>> +	ufshcd_suspend(hba);
>>   out:
>> -	if (ret)
>> -		dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
>>   	hba->is_powered = false;
>>   	/* allow force shutdown even in case of errors */
>>   	return 0;
>> @@ -9477,15 +9585,163 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>>   }
>>   EXPORT_SYMBOL_GPL(ufshcd_init);
>>   
>> +void ufshcd_resume_complete(struct device *dev)
>> +{
>> +	struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +	pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
>> +}
>> +EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
>> +
>> +int ufshcd_suspend_prepare(struct device *dev)
>> +{
>> +	struct ufs_hba *hba = dev_get_drvdata(dev);
>> +
>> +	/*
>> +	 * SCSI assumes that runtime-pm and system-pm for scsi drivers
>> +	 * are same. And it doesn't wake up the device for system-suspend
>> +	 * if it's runtime suspended. But ufs doesn't follow that.
>> +	 * The rpm-lvl and spm-lvl can be different in ufs.
>> +	 * Force it to honor system-suspend.
>> +	 */
>> +	scsi_autopm_get_device(hba->sdev_ufs_device);
>> +	/* Refer ufshcd_resume_complete() */
>> +	pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
>> +	scsi_autopm_put_device(hba->sdev_ufs_device);
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int ufshcd_wl_poweroff(struct device *dev)
>> +{
>> +	ufshcd_wl_shutdown(dev);
>> +	return 0;
>> +}
>> +#endif
>> +
>> +static int ufshcd_wl_probe(struct device *dev)
>> +{
>> +	return is_device_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
> 
> The "ufs_device_wlun" driver owns PM for sdev_ufs_device because it
> provides the dev_pm_ops.  This is where the pm_runtime_allow() belongs
> and it is symmetrical with the pm_runtime_forbid() in ufshcd_wl_remove().
> 
> 	if (!is_device_wlun(to_scsi_device(dev)))
> 		return -ENODEV;
> 	blk_pm_runtime_init(dev);
> 	pm_runtime_set_autosuspend_delay(dev, 0);
> 	pm_runtime_allow(dev);
> 
> Note sdev_ufs_device will not runtime suspend here unless the
> device links have been added and all consumers have suspended.
> That is handled separately by the pm_runtime_get_noresume() in
> ufshcd_slave_configure() and the pm_runtime_put() when luns_avail == 1
> in ufshcd_setup_links().
> 
>> +}
>> +
>> +static int ufshcd_wl_remove(struct device *dev)
>> +{
>> +	pm_runtime_forbid(dev);
>> +	return 0;
>> +}
>> +
>> +static const struct dev_pm_ops ufshcd_wl_pm_ops = {
>> +#ifdef CONFIG_PM_SLEEP
>> +	.suspend = ufshcd_wl_suspend,
>> +	.resume = ufshcd_wl_resume,
>> +	.freeze = ufshcd_wl_suspend,
>> +	.thaw = ufshcd_wl_resume,
>> +	.poweroff = ufshcd_wl_poweroff,
>> +	.restore = ufshcd_wl_resume,
>> +#endif
>> +	SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
>> +};
>> +
>> +/**
>> + * ufs_dev_wlun_template - describes ufs device wlun
>> + * ufs-device wlun - used to send pm commands
>> + * All luns are consumers of ufs-device wlun.
>> + *
>> + * Currently, no sd driver is present for wluns.
>> + * Hence the no specific pm operations are performed.
>> + * With ufs design, SSU should be sent to ufs-device wlun.
>> + * Hence register a scsi driver for ufs wluns only.
>> + */
>> +static struct scsi_driver ufs_dev_wlun_template = {
>> +	.gendrv = {
>> +		.name = "ufs_device_wlun",
>> +		.owner = THIS_MODULE,
>> +		.probe = ufshcd_wl_probe,
>> +		.remove = ufshcd_wl_remove,
>> +		.pm = &ufshcd_wl_pm_ops,
>> +		.shutdown = ufshcd_wl_shutdown,
>> +	},
>> +};
>> +
>> +static int ufshcd_rpmb_probe(struct device *dev)
>> +{
>> +	return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
>> +}
>> +
>> +static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
>> +{
>> +	int ret = 0;
>> +
>> +	if (!hba->wlun_rpmb_clr_ua)
>> +		return 0;
>> +	ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
>> +	if (!ret)
>> +		hba->wlun_rpmb_clr_ua = 0;
>> +	return ret;
>> +}
>> +
>> +static int ufshcd_rpmb_runtime_resume(struct device *dev)
>> +{
>> +	struct ufs_hba *hba = wlun_dev_to_hba(dev);
>> +
>> +	if (hba->sdev_rpmb)
>> +		return ufshcd_clear_rpmb_uac(hba);
>> +	return 0;
>> +}
>> +
>> +static int ufshcd_rpmb_resume(struct device *dev)
>> +{
>> +	struct ufs_hba *hba = wlun_dev_to_hba(dev);
>> +
>> +	if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
>> +		return ufshcd_clear_rpmb_uac(hba);
>> +	return 0;
>> +}
>> +
>> +static const struct dev_pm_ops ufs_rpmb_pm_ops = {
>> +	SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
>> +	SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
>> +};
>> +
>> +/**
>> + * Describes the ufs rpmb wlun.
>> + * Used only to send uac.
>> + */
>> +static struct scsi_driver ufs_rpmb_wlun_template = {
>> +	.gendrv = {
>> +		.name = "ufs_rpmb_wlun",
>> +		.owner = THIS_MODULE,
>> +		.probe = ufshcd_rpmb_probe,
>> +		.pm = &ufs_rpmb_pm_ops,
>> +	},
>> +};
>> +
>>   static int __init ufshcd_core_init(void)
>>   {
>> +	int ret;
>> +
>>   	ufs_debugfs_init();
>> +
>> +	ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
>> +	if (ret) {
>> +		ufs_debugfs_exit();
>> +		return ret;
>> +	}
>> +	ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
>> +	if (ret) {
>> +		ufs_debugfs_exit();
>> +		scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>> +		return ret;
>> +	}
>>   	return 0;
>>   }
>>   
>>   static void __exit ufshcd_core_exit(void)
>>   {
>>   	ufs_debugfs_exit();
>> +	scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>> +	scsi_unregister_driver(&ufs_rpmb_wlun_template.gendrv);
>>   }
>>   
>>   module_init(ufshcd_core_init);
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index ee61f82..7841b2a 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -72,6 +72,8 @@ enum ufs_event_type {
>>   	UFS_EVT_LINK_STARTUP_FAIL,
>>   	UFS_EVT_RESUME_ERR,
>>   	UFS_EVT_SUSPEND_ERR,
>> +	UFS_EVT_WL_SUSP_ERR,
>> +	UFS_EVT_WL_RES_ERR,
>>   
>>   	/* abnormal events */
>>   	UFS_EVT_DEV_RESET,
>> @@ -804,6 +806,7 @@ struct ufs_hba {
>>   	struct list_head clk_list_head;
>>   
>>   	bool wlun_dev_clr_ua;
>> +	bool wlun_rpmb_clr_ua;
>>   
>>   	/* Number of requests aborts */
>>   	int req_abort_count;
>> @@ -841,6 +844,7 @@ struct ufs_hba {
>>   #ifdef CONFIG_DEBUG_FS
>>   	struct dentry *debugfs_root;
>>   #endif
>> +	u32 luns_avail;
>>   };
>>   
>>   /* Returns true if clocks can be gated. Otherwise false */
>> @@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
>>   			     enum query_opcode desc_op);
>>   
>>   int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
>> +int ufshcd_suspend_prepare(struct device *dev);
>> +void ufshcd_resume_complete(struct device *dev);
>>   
>>   /* Wrapper functions for safely calling variant operations */
>>   static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
>> diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
>> index e151477..d9d233b 100644
>> --- a/include/trace/events/ufs.h
>> +++ b/include/trace/events/ufs.h
>> @@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
>>   		      int dev_state, int link_state),
>>   	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>   
>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      int dev_state, int link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      int dev_state, int link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      int dev_state, int link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
>> +	     TP_PROTO(const char *dev_name, int err, s64 usecs,
>> +		      int dev_state, int link_state),
>> +	     TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>> +
>>   TRACE_EVENT(ufshcd_command,
>>   	TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
>>   		 unsigned int tag, u32 doorbell, int transfer_len, u32 intr,
>>
> 


-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Adrian Hunter]

On 22/03/21 9:53 pm, Asutosh Das (asd) wrote:
> On 3/19/2021 10:47 AM, Adrian Hunter wrote:
>> On 19/03/21 2:35 am, Asutosh Das wrote:
>>> During runtime-suspend of ufs host, the scsi devices are
>>> already suspended and so are the queues associated with them.
>>> But the ufs host sends SSU to wlun during its runtime-suspend.
>>> During the process blk_queue_enter checks if the queue is not in
>>> suspended state. If so, it waits for the queue to resume, and never
>>> comes out of it.
>>> The commit
>>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>>> adds the check if the queue is in suspended state in blk_queue_enter().
>>>
>>> Call trace:
>>>   __switch_to+0x174/0x2c4
>>>   __schedule+0x478/0x764
>>>   schedule+0x9c/0xe0
>>>   blk_queue_enter+0x158/0x228
>>>   blk_mq_alloc_request+0x40/0xa4
>>>   blk_get_request+0x2c/0x70
>>>   __scsi_execute+0x60/0x1c4
>>>   ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>>   ufshcd_suspend+0x208/0x83c
>>>   ufshcd_runtime_suspend+0x40/0x154
>>>   ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>>   pm_generic_runtime_suspend+0x28/0x3c
>>>   __rpm_callback+0x80/0x2a4
>>>   rpm_suspend+0x308/0x614
>>>   rpm_idle+0x158/0x228
>>>   pm_runtime_work+0x84/0xac
>>>   process_one_work+0x1f0/0x470
>>>   worker_thread+0x26c/0x4c8
>>>   kthread+0x13c/0x320
>>>   ret_from_fork+0x10/0x18
>>>
>>> Fix this by registering ufs device wlun as a scsi driver and
>>> registering it for block runtime-pm. Also make this as a
>>> supplier for all other luns. That way, this device wlun
>>> suspends after all the consumers and resumes after
>>> hba resumes.
>>>
>>> Co-developed-by: Can Guo <cang@codeaurora.org>
>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>>
>> I have some more comments that may help straighten things out.
>>
>> Also please look at ufs_debugfs_get_user_access() and
>> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
>> sdev_ufs_device.
>>
>> It would also be good if you could re-base on linux-next.
>>
> 
> Hi Adrian
> Thanks for the comments.
> 
> I agree moving the code to wlun probe and other changes.
> But it looks to me that it may not fully solve the issue.
> 
> Please let me explain my understanding on this:
> 
> (Please refer to the logs in v10)
> scsi_autopm_*() are invoked on a sdev.
> pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.
> 
> For the device wlun:
>     slave_configure():
>         - doesn't set the rpm_autosuspend
>         - pm_runtime_getnoresume()
>     scsi_sysfs_add_sdev():
>         - pm_runtime_forbid()
>         - scsi_autopm_get_device()
>         - device_add()
>             - ufshcd_wl_probe()
>         - scsi_autopm_put_device()
> 
> For all other scsi devices:
>     slave_alloc():
>         - ufshcd_setup_links()
> Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);

With DL_FLAG_RPM_ACTIVE, links will 'get' not 'put'

>     slave_configure():
>         - set rpm_autosuspend
>     scsi_sysfs_add_sdev():
>         - scsi_autopm_get_device()
>         - device_add() -> schedules an async probe()
>         - scsi_autopm_put_device() - (1)
> 
> Now the rpm_put_suppliers() can be invoked *after* pm_runtime_get_suppliers() of the async probe(), since both are running in different contexts.

Only if the sd device suspends.

> In that case, the usage_count of supplier would be decremented until rpm_active of this link becomes 1.

Right, because the sd device suspended.

> Now the pm_runtime_get_suppliers() expects the link_active to be more than 1.

Not sure what you mean here. pm_runtime_*put*_suppliers() won't do anything if the link count is 1.

> Now then, there comes a time, that when sd_probe() schedules a suspend, the supplier usage_count becomes 0 and the link_active becomes 1.
> And the supplier suspends before the consumer.

sd probe first resumes the sd device which will resume the supplier.

> 
> So I was wondering, what'd make sure that the pm_runtime_get_suppliers() from driver_probe_device() is invoked after scsi_autopm_put_device() (1) finishes the rpm_put_suppliers().
> 
> Am not sure if I'm missing something in this.
> Do you think, the current changes alone can fix the above issue?

Yes, but let's see.

> 
> -asd
> 
>>> ---
>>>   drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
>>>   drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
>>>   drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
>>>   drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
>>>   drivers/scsi/ufs/ufs-exynos.c      |   2 +
>>>   drivers/scsi/ufs/ufs-hisi.c        |   2 +
>>>   drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
>>>   drivers/scsi/ufs/ufs-qcom.c        |   2 +
>>>   drivers/scsi/ufs/ufs_bsg.c         |   6 +-
>>>   drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
>>>   drivers/scsi/ufs/ufshcd.c          | 622 ++++++++++++++++++++++++++-----------
>>>   drivers/scsi/ufs/ufshcd.h          |   6 +
>>>   include/trace/events/ufs.h         |  20 ++
>>>   13 files changed, 491 insertions(+), 225 deletions(-)
>>>
>>> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
>>> index 149391f..3e70c23 100644
>>> --- a/drivers/scsi/ufs/cdns-pltfrm.c
>>> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
>>> @@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
>>>       .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>       .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>       .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static struct platform_driver cdns_ufs_pltfrm_driver = {
>>> diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>> index 67a6a61..b01db12 100644
>>> --- a/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>> +++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>> @@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
>>>       .runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
>>>       .runtime_resume  = tc_dwc_g210_pci_runtime_resume,
>>>       .runtime_idle    = tc_dwc_g210_pci_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {
>>> diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
>>> index dee98dc..06457d5 100644
>>> --- a/drivers/scsi/ufs/ufs-debugfs.c
>>> +++ b/drivers/scsi/ufs/ufs-debugfs.c
>>> @@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
>>>       ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
>>>   }
>>>   -void __exit ufs_debugfs_exit(void)
>>> +void ufs_debugfs_exit(void)
>>>   {
>>>       debugfs_remove_recursive(ufs_debugfs_root);
>>>   }
>>> diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
>>> index f35b39c..12c2730 100644
>>> --- a/drivers/scsi/ufs/ufs-debugfs.h
>>> +++ b/drivers/scsi/ufs/ufs-debugfs.h
>>> @@ -9,7 +9,7 @@ struct ufs_hba;
>>>     #ifdef CONFIG_DEBUG_FS
>>>   void __init ufs_debugfs_init(void);
>>> -void __exit ufs_debugfs_exit(void);
>>> +void ufs_debugfs_exit(void);
>>>   void ufs_debugfs_hba_init(struct ufs_hba *hba);
>>>   void ufs_debugfs_hba_exit(struct ufs_hba *hba);
>>>   #else
>>> diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
>>> index 267943a1..45c0b02 100644
>>> --- a/drivers/scsi/ufs/ufs-exynos.c
>>> +++ b/drivers/scsi/ufs/ufs-exynos.c
>>> @@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
>>>       .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>       .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>       .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static struct platform_driver exynos_ufs_pltform = {
>>> diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
>>> index 0aa5813..d463b44 100644
>>> --- a/drivers/scsi/ufs/ufs-hisi.c
>>> +++ b/drivers/scsi/ufs/ufs-hisi.c
>>> @@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
>>>       .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>       .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>       .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static struct platform_driver ufs_hisi_pltform = {
>>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
>>> index c55202b..51c82e3 100644
>>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>>> @@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
>>>       /* enable unipro clock gating feature */
>>>       ufs_mtk_cfg_unipro_cg(hba, true);
>>>   -    /* configure auto-hibern8 timer to 10ms */
>>> -    if (ufshcd_is_auto_hibern8_supported(hba)) {
>>> -        ufshcd_auto_hibern8_update(hba,
>>> -            FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>>> -            FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
>>> -    }
>>> +    /* will be configured during probe hba */
>>> +    if (ufshcd_is_auto_hibern8_supported(hba))
>>> +        hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>>> +            FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
>>>         ufs_mtk_setup_clk_gating(hba);
>>>   @@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
>>>       .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>       .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>       .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static struct platform_driver ufs_mtk_pltform = {
>>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>>> index f97d7b0..9aa098a 100644
>>> --- a/drivers/scsi/ufs/ufs-qcom.c
>>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>>> @@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
>>>       .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>       .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>       .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>> +    .prepare     = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>>   };
>>>     static struct platform_driver ufs_qcom_pltform = {
>>> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
>>> index 5b2bc1a..cbb5a90 100644
>>> --- a/drivers/scsi/ufs/ufs_bsg.c
>>> +++ b/drivers/scsi/ufs/ufs_bsg.c
>>> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>         bsg_reply->reply_payload_rcv_len = 0;
>>>   -    pm_runtime_get_sync(hba->dev);
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>         msgcode = bsg_request->msgcode;
>>>       switch (msgcode) {
>>> @@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>           ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
>>>                           &desc_len, desc_op);
>>>           if (ret) {
>>> -            pm_runtime_put_sync(hba->dev);
>>> +            scsi_autopm_put_device(hba->sdev_ufs_device);
>>>               goto out;
>>>           }
>>>   @@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>           break;
>>>       }
>>>   -    pm_runtime_put_sync(hba->dev);
>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>         if (!desc_buff)
>>>           goto out;
>>> diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
>>> index fadd566..5d4ffd2 100644
>>> --- a/drivers/scsi/ufs/ufshcd-pci.c
>>> +++ b/drivers/scsi/ufs/ufshcd-pci.c
>>> @@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
>>>       return ufshcd_system_resume(dev_get_drvdata(dev));
>>>   }
>>>   -/**
>>> - * ufshcd_pci_poweroff - suspend-to-disk poweroff function
>>> - * @dev: pointer to PCI device handle
>>> - *
>>> - * Returns 0 if successful
>>> - * Returns non-zero otherwise
>>> - */
>>> -static int ufshcd_pci_poweroff(struct device *dev)
>>> -{
>>> -    struct ufs_hba *hba = dev_get_drvdata(dev);
>>> -    int spm_lvl = hba->spm_lvl;
>>> -    int ret;
>>> -
>>> -    /*
>>> -     * For poweroff we need to set the UFS device to PowerDown mode.
>>> -     * Force spm_lvl to ensure that.
>>> -     */
>>> -    hba->spm_lvl = 5;
>>> -    ret = ufshcd_system_suspend(hba);
>>> -    hba->spm_lvl = spm_lvl;
>>> -    return ret;
>>> -}
>>> -
>>>   #endif /* !CONFIG_PM_SLEEP */
>>>     #ifdef CONFIG_PM
>>> @@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>>   }
>>>     static const struct dev_pm_ops ufshcd_pci_pm_ops = {
>>> -#ifdef CONFIG_PM_SLEEP
>>> -    .suspend    = ufshcd_pci_suspend,
>>> -    .resume        = ufshcd_pci_resume,
>>> -    .freeze        = ufshcd_pci_suspend,
>>> -    .thaw        = ufshcd_pci_resume,
>>> -    .poweroff    = ufshcd_pci_poweroff,
>>> -    .restore    = ufshcd_pci_resume,
>>> -#endif
>>>       SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
>>>                  ufshcd_pci_runtime_resume,
>>>                  ufshcd_pci_runtime_idle)
>>> +    SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
>>> +#ifdef CONFIG_PM_SLEEP
>>> +    .prepare    = ufshcd_suspend_prepare,
>>> +    .complete    = ufshcd_resume_complete,
>>> +#endif
>>>   };
>>>     static const struct pci_device_id ufshcd_pci_tbl[] = {
>>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>>> index 45624c7..7106cb8 100644
>>> --- a/drivers/scsi/ufs/ufshcd.c
>>> +++ b/drivers/scsi/ufs/ufshcd.c
>>> @@ -16,6 +16,7 @@
>>>   #include <linux/bitfield.h>
>>>   #include <linux/blk-pm.h>
>>>   #include <linux/blkdev.h>
>>> +#include <scsi/scsi_driver.h>
>>>   #include "ufshcd.h"
>>>   #include "ufs_quirks.h"
>>>   #include "unipro.h"
>>> @@ -78,6 +79,8 @@
>>>   /* Polling time to wait for fDeviceInit */
>>>   #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
>>>   +#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
>>> +
>>>   #define ufshcd_toggle_vreg(_dev, _vreg, _on)                \
>>>       ({                                                              \
>>>           int _ret;                                               \
>>> @@ -1556,7 +1559,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>>       if (value == hba->clk_scaling.is_enabled)
>>>           goto out;
>>>   -    pm_runtime_get_sync(hba->dev);
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>       ufshcd_hold(hba, false);
>>>         hba->clk_scaling.is_enabled = value;
>>> @@ -1572,7 +1575,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>>       }
>>>         ufshcd_release(hba);
>>> -    pm_runtime_put_sync(hba->dev);
>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>   out:
>>>       up(&hba->host_sem);
>>>       return err ? err : count;
>>> @@ -2572,6 +2575,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
>>>       return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
>>>   }
>>>   +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
>>> +{
>>> +    return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
>>> +}
>>> +
>>> +static inline bool is_device_wlun(struct scsi_device *sdev)
>>> +{
>>> +    return (sdev->lun ==
>>> +        ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
>>> +}
>>> +
>>>   static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
>>>   {
>>>       struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
>>> @@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
>>>       spin_unlock_irqrestore(hba->host->host_lock, flags);
>>>         if (update && !pm_runtime_suspended(hba->dev)) {
>>> -        pm_runtime_get_sync(hba->dev);
>>> +        scsi_autopm_get_device(hba->sdev_ufs_device);
>>>           ufshcd_hold(hba, false);
>>>           ufshcd_auto_hibern8_enable(hba);
>>>           ufshcd_release(hba);
>>> -        pm_runtime_put(hba->dev);
>>> +        scsi_autopm_put_device(hba->sdev_ufs_device);
>>>       }
>>>   }
>>>   EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
>>> @@ -4808,6 +4822,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
>>>   }
>>>     /**
>>> + * ufshcd_setup_links - associate link b/w device wlun and other luns
>>> + * @sdev: pointer to SCSI device
>>> + * @hba: pointer to ufs hba
>>> + */
>>> +static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
>>> +{
>>> +    struct device_link *link;
>>> +
>>> +    /*
>>> +     * device wlun is the supplier & rest of the luns are consumers
>>> +     * This ensures that device wlun suspends after all other luns.
>>> +     */
>>> +    if (hba->sdev_ufs_device) {
>>> +        link = device_link_add(&sdev->sdev_gendev,
>>> +                       &hba->sdev_ufs_device->sdev_gendev,
>>> +                       DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
>>> +        if (!link) {
>>> +            dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
>>> +                dev_name(&hba->sdev_ufs_device->sdev_gendev));
>>> +            return;
>>> +        }
>>> +        hba->luns_avail--;
>>> +        /* Ignore REPORT_LUN wlun probing */
>>> +        if (hba->luns_avail != 1) {
>>
>> The condition here is the wrong way around. i.e. should be
>>
>>         if (hba->luns_avail == 1) {
>>
>>> +            pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
>>
>> If the usage_count is zero here, then we should let it suspend i.e. make this:
>>
>>             pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>
>> Note this pairs with the pm_runtime_get_noresume() that needs to be added
>> to ufshcd_slave_configure.  Please see comments for ufshcd_slave_configure().
>>
>>
>>> +            pm_runtime_allow(&hba->sdev_ufs_device->sdev_gendev);
>>
>> This pm_runtime_allow should not be here.  It should be in ufshcd_wl_probe().
>> Please see comments for ufshcd_wl_probe().
>>
>>> +            return;
>>> +        }
>>> +    } else {
>>> +        /* device wlun is probed */
>>> +        hba->luns_avail--;
>>> +    }
>>> +}
>>> +
>>> +/**
>>>    * ufshcd_slave_alloc - handle initial SCSI device configurations
>>>    * @sdev: pointer to SCSI device
>>>    *
>>> @@ -4838,6 +4887,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
>>>         ufshcd_get_lu_power_on_wp_status(hba, sdev);
>>>   +    ufshcd_setup_links(hba, sdev);
>>> +
>>>       return 0;
>>>   }
>>>   @@ -4869,8 +4920,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
>>>       blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
>>>       if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
>>>           blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
>>> -
>>> -    if (ufshcd_is_rpm_autosuspend_allowed(hba))
>>> +    /*
>>> +     * Block runtime-pm until all consumers are added.
>>> +     * Refer ufshcd_setup_links().
>>> +     */
>>> +    if (is_device_wlun(sdev))
>>> +        pm_runtime_forbid(&sdev->sdev_gendev);
>>
>> Since rpm_autosuspend is not being set for sdev_ufs_device, scsi_sysfs_add_sdev()
>> will pm_runtime_forbid() it anyway.  We should increase the usage_count instead
>> i.e.
>>
>>         pm_runtime_get_noresume(&sdev->sdev_gendev);
>>
>>> +    else if (ufshcd_is_rpm_autosuspend_allowed(hba))
>>>           sdev->rpm_autosuspend = 1;
>>>         ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
>>> @@ -4985,15 +5041,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>>>                * UFS device needs urgent BKOPs.
>>>                */
>>>               if (!hba->pm_op_in_progress &&
>>> -                ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
>>> -                schedule_work(&hba->eeh_work)) {
>>> -                /*
>>> -                 * Prevent suspend once eeh_work is scheduled
>>> -                 * to avoid deadlock between ufshcd_suspend
>>> -                 * and exception event handler.
>>> -                 */
>>> -                pm_runtime_get_noresume(hba->dev);
>>> -            }
>>> +                ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
>>> +                /* Flushed in suspend */
>>> +                schedule_work(&hba->eeh_work);
>>>               break;
>>>           case UPIU_TRANSACTION_REJECT_UPIU:
>>>               /* TODO: handle Reject UPIU Response */
>>> @@ -5589,8 +5639,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
>>>        * after a certain delay to recheck the threshold by next runtime
>>>        * suspend.
>>>        */
>>> -    pm_runtime_get_sync(hba->dev);
>>> -    pm_runtime_put_sync(hba->dev);
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>   }
>>>     /**
>>> @@ -5607,7 +5657,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>>       u32 status = 0;
>>>       hba = container_of(work, struct ufs_hba, eeh_work);
>>>   -    pm_runtime_get_sync(hba->dev);
>>>       ufshcd_scsi_block_requests(hba);
>>>       err = ufshcd_get_ee_status(hba, &status);
>>>       if (err) {
>>> @@ -5623,14 +5672,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>>     out:
>>>       ufshcd_scsi_unblock_requests(hba);
>>> -    /*
>>> -     * pm_runtime_get_noresume is called while scheduling
>>> -     * eeh_work to avoid suspend racing with exception work.
>>> -     * Hence decrement usage counter using pm_runtime_put_noidle
>>> -     * to allow suspend on completion of exception event handler.
>>> -     */
>>> -    pm_runtime_put_noidle(hba->dev);
>>> -    pm_runtime_put(hba->dev);
>>>       return;
>>>   }
>>>   @@ -5755,12 +5796,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
>>>     static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
>>>   {
>>> -    pm_runtime_get_sync(hba->dev);
>>> -    if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>> +    if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
>>> +        hba->is_sys_suspended) {
>>>           enum ufs_pm_op pm_op;
>>>             /*
>>> -         * Don't assume anything of pm_runtime_get_sync(), if
>>> +         * Don't assume anything of resume, if
>>>            * resume fails, irq and clocks can be OFF, and powers
>>>            * can be OFF or in LPM.
>>>            */
>>> @@ -5789,7 +5831,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>>>       ufshcd_release(hba);
>>>       if (ufshcd_is_clkscaling_supported(hba))
>>>           ufshcd_clk_scaling_suspend(hba, false);
>>> -    pm_runtime_put(hba->dev);
>>> +    pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>>   }
>>>     static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
>>> @@ -5810,14 +5852,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
>>>         hba->is_sys_suspended = false;
>>>       /*
>>> -     * Set RPM status of hba device to RPM_ACTIVE,
>>> +     * Set RPM status of wlun device to RPM_ACTIVE,
>>>        * this also clears its runtime error.
>>>        */
>>> -    ret = pm_runtime_set_active(hba->dev);
>>> +    ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
>>>       /*
>>> -     * If hba device had runtime error, we also need to resume those
>>> -     * scsi devices under hba in case any of them has failed to be
>>> -     * resumed due to hba runtime resume failure. This is to unblock
>>> +     * If wlun device had runtime error, we also need to resume those
>>> +     * consumer scsi devices in case any of them has failed to be
>>> +     * resumed due to supplier runtime resume failure. This is to unblock
>>>        * blk_queue_enter in case there are bios waiting inside it.
>>>        */
>>>       if (!ret) {
>>> @@ -7207,11 +7249,12 @@ static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
>>>     static inline void ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
>>>   {
>>> +    int dly = is_device_wlun(sdev) ? 0:RPM_AUTOSUSPEND_DELAY_MS;
>>> +
>>>       scsi_autopm_get_device(sdev);
>>>       blk_pm_runtime_init(sdev->request_queue, &sdev->sdev_gendev);
>>>       if (sdev->rpm_autosuspend)
>>> -        pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev,
>>> -                         RPM_AUTOSUSPEND_DELAY_MS);
>>> +        pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev, dly);
>>>       scsi_autopm_put_device(sdev);
>>>   }
>>>   @@ -7253,6 +7296,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>>>           hba->sdev_ufs_device = NULL;
>>>           goto out;
>>>       }
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>       ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
>>
>> Let's drop both scsi_autopm_get_device() and ufshcd_blk_pm_runtime_init()
>> here and instead do things in ufshcd_wl_probe() - see comments for ufshcd_wl_probe()
>>
>>>       scsi_device_put(hba->sdev_ufs_device);
>>>   @@ -7417,6 +7461,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>>>           goto out;
>>>       }
>>>   +    hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
>>> +        desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
>>> +
>>>       ufs_fixup_device_setup(hba);
>>>         ufshcd_wb_probe(hba, desc_buf);
>>> @@ -7892,6 +7939,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
>>>       ufshcd_set_ufs_dev_active(hba);
>>>       ufshcd_force_reset_auto_bkops(hba);
>>>       hba->wlun_dev_clr_ua = true;
>>> +    hba->wlun_rpmb_clr_ua = true;
>>>         /* Gear up to HS gear if supported */
>>>       if (hba->max_pwr_info.is_valid) {
>>> @@ -8475,7 +8523,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
>>>        * handling context.
>>>        */
>>>       hba->host->eh_noresume = 1;
>>> -    ufshcd_clear_ua_wluns(hba);
>>> +    if (hba->wlun_dev_clr_ua)
>>> +        ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
>>>         cmd[4] = pwr_mode << 4;
>>>   @@ -8650,23 +8699,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
>>>           ufshcd_setup_hba_vreg(hba, true);
>>>   }
>>>   -/**
>>> - * ufshcd_suspend - helper function for suspend operations
>>> - * @hba: per adapter instance
>>> - * @pm_op: desired low power operation type
>>> - *
>>> - * This function will try to put the UFS device and link into low power
>>> - * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
>>> - * (System PM level).
>>> - *
>>> - * If this function is called during shutdown, it will make sure that
>>> - * both UFS device and UFS link is powered off.
>>> - *
>>> - * NOTE: UFS device & link must be active before we enter in this function.
>>> - *
>>> - * Returns 0 for success and non-zero for failure
>>> - */
>>> -static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>> +static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>   {
>>>       int ret = 0;
>>>       int check_for_bkops;
>>> @@ -8674,7 +8707,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>       enum ufs_dev_pwr_mode req_dev_pwr_mode;
>>>       enum uic_link_state req_link_state;
>>>   -    hba->pm_op_in_progress = 1;
>>> +    hba->pm_op_in_progress = true;
>>>       if (!ufshcd_is_shutdown_pm(pm_op)) {
>>>           pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
>>>                hba->rpm_lvl : hba->spm_lvl;
>>> @@ -8697,17 +8730,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>         if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
>>>               req_link_state == UIC_LINK_ACTIVE_STATE) {
>>> -        goto disable_clks;
>>> +        goto enable_scaling;
>>>       }
>>>         if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
>>>           (req_link_state == hba->uic_link_state))
>>> -        goto enable_gating;
>>> +        goto enable_scaling;
>>>         /* UFS device & link must be active before we enter in this function */
>>>       if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
>>>           ret = -EINVAL;
>>> -        goto enable_gating;
>>> +        goto enable_scaling;
>>>       }
>>>         if (ufshcd_is_runtime_pm(pm_op)) {
>>> @@ -8719,7 +8752,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>                */
>>>               ret = ufshcd_urgent_bkops(hba);
>>>               if (ret)
>>> -                goto enable_gating;
>>> +                goto enable_scaling;
>>>           } else {
>>>               /* make sure that auto bkops is disabled */
>>>               ufshcd_disable_auto_bkops(hba);
>>> @@ -8747,7 +8780,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>           if (!hba->dev_info.b_rpm_dev_flush_capable) {
>>>               ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
>>>               if (ret)
>>> -                goto enable_gating;
>>> +                goto enable_scaling;
>>>           }
>>>       }
>>>   @@ -8760,7 +8793,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>       if (ret)
>>>           goto set_dev_active;
>>>   -disable_clks:
>>>       /*
>>>        * Call vendor specific suspend callback. As these callbacks may access
>>>        * vendor specific host controller register space call them before the
>>> @@ -8769,28 +8801,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>       ret = ufshcd_vops_suspend(hba, pm_op);
>>>       if (ret)
>>>           goto set_link_active;
>>> -    /*
>>> -     * Disable the host irq as host controller as there won't be any
>>> -     * host controller transaction expected till resume.
>>> -     */
>>> -    ufshcd_disable_irq(hba);
>>> -
>>> -    ufshcd_setup_clocks(hba, false);
>>> -
>>> -    if (ufshcd_is_clkgating_allowed(hba)) {
>>> -        hba->clk_gating.state = CLKS_OFF;
>>> -        trace_ufshcd_clk_gating(dev_name(hba->dev),
>>> -                    hba->clk_gating.state);
>>> -    }
>>> -
>>> -    ufshcd_vreg_set_lpm(hba);
>>> -
>>> -    /* Put the host controller in low power mode if possible */
>>> -    ufshcd_hba_vreg_set_lpm(hba);
>>>       goto out;
>>>     set_link_active:
>>> -    ufshcd_vreg_set_hpm(hba);
>>>       /*
>>>        * Device hardware reset is required to exit DeepSleep. Also, for
>>>        * DeepSleep, the link is off so host reset and restore will be done
>>> @@ -8812,57 +8825,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>       }
>>>       if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
>>>           ufshcd_disable_auto_bkops(hba);
>>> -enable_gating:
>>> +enable_scaling:
>>>       if (ufshcd_is_clkscaling_supported(hba))
>>>           ufshcd_clk_scaling_suspend(hba, false);
>>>   -    hba->clk_gating.is_suspended = false;
>>>       hba->dev_info.b_rpm_dev_flush_capable = false;
>>> -    ufshcd_clear_ua_wluns(hba);
>>> -    ufshcd_release(hba);
>>>   out:
>>>       if (hba->dev_info.b_rpm_dev_flush_capable) {
>>>           schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
>>>               msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
>>>       }
>>>   -    hba->pm_op_in_progress = 0;
>>> -
>>> -    if (ret)
>>> -        ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
>>> +    if (ret) {
>>> +        ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
>>> +        hba->clk_gating.is_suspended = false;
>>> +        ufshcd_release(hba);
>>> +    }
>>> +    hba->pm_op_in_progress = false;
>>>       return ret;
>>>   }
>>>   -/**
>>> - * ufshcd_resume - helper function for resume operations
>>> - * @hba: per adapter instance
>>> - * @pm_op: runtime PM or system PM
>>> - *
>>> - * This function basically brings the UFS device, UniPro link and controller
>>> - * to active state.
>>> - *
>>> - * Returns 0 for success and non-zero for failure
>>> - */
>>> -static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>> +static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>   {
>>>       int ret;
>>> -    enum uic_link_state old_link_state;
>>> +    enum uic_link_state old_link_state = hba->uic_link_state;
>>>   -    hba->pm_op_in_progress = 1;
>>> -    old_link_state = hba->uic_link_state;
>>> -
>>> -    ufshcd_hba_vreg_set_hpm(hba);
>>> -    ret = ufshcd_vreg_set_hpm(hba);
>>> -    if (ret)
>>> -        goto out;
>>> -
>>> -    /* Make sure clocks are enabled before accessing controller */
>>> -    ret = ufshcd_setup_clocks(hba, true);
>>> -    if (ret)
>>> -        goto disable_vreg;
>>> -
>>> -    /* enable the host irq as host controller would be active soon */
>>> -    ufshcd_enable_irq(hba);
>>> +    hba->pm_op_in_progress = true;
>>>         /*
>>>        * Call vendor specific resume callback. As these callbacks may access
>>> @@ -8871,7 +8859,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>        */
>>>       ret = ufshcd_vops_resume(hba, pm_op);
>>>       if (ret)
>>> -        goto disable_irq_and_vops_clks;
>>> +        goto out;
>>>         /* For DeepSleep, the only supported option is to have the link off */
>>>       WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
>>> @@ -8916,31 +8904,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>            */
>>>           ufshcd_urgent_bkops(hba);
>>>   -    hba->clk_gating.is_suspended = false;
>>> -
>>> -    if (ufshcd_is_clkscaling_supported(hba))
>>> -        ufshcd_clk_scaling_suspend(hba, false);
>>> -
>>> -    /* Enable Auto-Hibernate if configured */
>>> -    ufshcd_auto_hibern8_enable(hba);
>>> +    if (hba->clk_scaling.is_allowed)
>>> +        ufshcd_resume_clkscaling(hba);
>>>         if (hba->dev_info.b_rpm_dev_flush_capable) {
>>>           hba->dev_info.b_rpm_dev_flush_capable = false;
>>>           cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
>>>       }
>>>   -    ufshcd_clear_ua_wluns(hba);
>>> -
>>> -    /* Schedule clock gating in case of no access to UFS device yet */
>>> -    ufshcd_release(hba);
>>> -
>>> +    /* Enable Auto-Hibernate if configured */
>>> +    ufshcd_auto_hibern8_enable(hba);
>>>       goto out;
>>>     set_old_link_state:
>>>       ufshcd_link_state_transition(hba, old_link_state, 0);
>>>   vendor_suspend:
>>>       ufshcd_vops_suspend(hba, pm_op);
>>> -disable_irq_and_vops_clks:
>>> +out:
>>> +    if (ret)
>>> +        ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
>>> +    hba->clk_gating.is_suspended = false;
>>> +    ufshcd_release(hba);
>>> +    hba->pm_op_in_progress = false;
>>> +    return ret;
>>> +}
>>> +
>>> +static int ufshcd_wl_runtime_suspend(struct device *dev)
>>> +{
>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>> +    struct ufs_hba *hba;
>>> +    int ret;
>>> +    ktime_t start = ktime_get();
>>> +
>>> +    hba = shost_priv(sdev->host);
>>> +
>>> +    ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
>>> +    if (ret)
>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>> +
>>> +    trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int ufshcd_wl_runtime_resume(struct device *dev)
>>> +{
>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>> +    struct ufs_hba *hba;
>>> +    int ret = 0;
>>> +    ktime_t start = ktime_get();
>>> +
>>> +    hba = shost_priv(sdev->host);
>>> +
>>> +    ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
>>> +    if (ret)
>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>> +
>>> +    trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int ufshcd_wl_suspend(struct device *dev)
>>> +{
>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>> +    struct ufs_hba *hba;
>>> +    int ret;
>>> +    ktime_t start = ktime_get();
>>> +
>>> +    hba = shost_priv(sdev->host);
>>> +    ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
>>> +    if (ret)
>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__,  ret);
>>> +
>>> +    trace_ufshcd_wl_suspend(dev_name(dev), ret,
>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int ufshcd_wl_resume(struct device *dev)
>>> +{
>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>> +    struct ufs_hba *hba;
>>> +    int ret = 0;
>>> +    ktime_t start = ktime_get();
>>> +
>>> +    if (pm_runtime_suspended(dev))
>>> +        return 0;
>>> +    hba = shost_priv(sdev->host);
>>> +
>>> +    ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
>>> +    if (ret)
>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>> +
>>> +    trace_ufshcd_wl_resume(dev_name(dev), ret,
>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> +
>>> +    return ret;
>>> +}
>>> +#endif
>>> +
>>> +static void ufshcd_wl_shutdown(struct device *dev)
>>> +{
>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>> +    struct ufs_hba *hba;
>>> +
>>> +    hba = shost_priv(sdev->host);
>>> +    /* Turn on everything while shutting down */
>>> +    scsi_autopm_get_device(sdev);
>>> +    scsi_device_quiesce(sdev);
>>> +    shost_for_each_device(sdev, hba->host) {
>>> +        if (sdev == hba->sdev_ufs_device)
>>> +            continue;
>>> +        scsi_device_quiesce(sdev);
>>> +    }
>>> +    __ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
>>> +}
>>> +
>>> +/**
>>> + * ufshcd_suspend - helper function for suspend operations
>>> + * @hba: per adapter instance
>>> + *
>>> + * This function will put disable irqs, turn off clocks
>>> + * and set vreg and hba-vreg in lpm mode.
>>> + * Also check the description of __ufshcd_wl_suspend().
>>> + */
>>> +static void ufshcd_suspend(struct ufs_hba *hba)
>>> +{
>>> +    hba->pm_op_in_progress = 1;
>>> +
>>> +    /*
>>> +     * Disable the host irq as host controller as there won't be any
>>> +     * host controller transaction expected till resume.
>>> +     */
>>>       ufshcd_disable_irq(hba);
>>>       ufshcd_setup_clocks(hba, false);
>>>       if (ufshcd_is_clkgating_allowed(hba)) {
>>> @@ -8948,6 +9052,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>           trace_ufshcd_clk_gating(dev_name(hba->dev),
>>>                       hba->clk_gating.state);
>>>       }
>>> +
>>> +    ufshcd_vreg_set_lpm(hba);
>>> +    /* Put the host controller in low power mode if possible */
>>> +    ufshcd_hba_vreg_set_lpm(hba);
>>> +    hba->pm_op_in_progress = 0;
>>> +}
>>> +
>>> +/**
>>> + * ufshcd_resume - helper function for resume operations
>>> + * @hba: per adapter instance
>>> + *
>>> + * This function basically turns on the regulators, clocks and
>>> + * irqs of the hba.
>>> + * Also check the description of __ufshcd_wl_resume().
>>> + *
>>> + * Returns 0 for success and non-zero for failure
>>> + */
>>> +static int ufshcd_resume(struct ufs_hba *hba)
>>> +{
>>> +    int ret;
>>> +
>>> +    hba->pm_op_in_progress = 1;
>>> +
>>> +    ufshcd_hba_vreg_set_hpm(hba);
>>> +    ret = ufshcd_vreg_set_hpm(hba);
>>> +    if (ret)
>>> +        goto out;
>>> +
>>> +    /* Make sure clocks are enabled before accessing controller */
>>> +    ret = ufshcd_setup_clocks(hba, true);
>>> +    if (ret)
>>> +        goto disable_vreg;
>>> +
>>> +    /* enable the host irq as host controller would be active soon */
>>> +    ufshcd_enable_irq(hba);
>>> +    goto out;
>>> +
>>>   disable_vreg:
>>>       ufshcd_vreg_set_lpm(hba);
>>>   out:
>>> @@ -8962,6 +9103,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>    * @hba: per adapter instance
>>>    *
>>>    * Check the description of ufshcd_suspend() function for more details.
>>> + * Also check the description of __ufshcd_wl_suspend().
>>>    *
>>>    * Returns 0 for success and non-zero for failure
>>>    */
>>> @@ -8987,21 +9129,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
>>>            !hba->dev_info.b_rpm_dev_flush_capable)
>>>           goto out;
>>>   -    if (pm_runtime_suspended(hba->dev)) {
>>> -        /*
>>> -         * UFS device and/or UFS link low power states during runtime
>>> -         * suspend seems to be different than what is expected during
>>> -         * system suspend. Hence runtime resume the devic & link and
>>> -         * let the system suspend low power states to take effect.
>>> -         * TODO: If resume takes longer time, we might have optimize
>>> -         * it in future by not resuming everything if possible.
>>> -         */
>>> -        ret = ufshcd_runtime_resume(hba);
>>> -        if (ret)
>>> -            goto out;
>>> -    }
>>> -
>>> -    ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
>>> +    ufshcd_suspend(hba);
>>>   out:
>>>       trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
>>>           ktime_to_us(ktime_sub(ktime_get(), start)),
>>> @@ -9023,7 +9151,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
>>>     int ufshcd_system_resume(struct ufs_hba *hba)
>>>   {
>>> -    int ret = 0;
>>>       ktime_t start = ktime_get();
>>>         if (!hba)
>>> @@ -9034,22 +9161,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
>>>           down(&hba->host_sem);
>>>       }
>>>   -    if (!hba->is_powered || pm_runtime_suspended(hba->dev))
>>> -        /*
>>> -         * Let the runtime resume take care of resuming
>>> -         * if runtime suspended.
>>> -         */
>>> +    if (!hba->is_powered)
>>>           goto out;
>>>       else
>>> -        ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
>>> +        ufshcd_resume(hba);
>>>   out:
>>> -    trace_ufshcd_system_resume(dev_name(hba->dev), ret,
>>> +    trace_ufshcd_system_resume(dev_name(hba->dev), 0,
>>>           ktime_to_us(ktime_sub(ktime_get(), start)),
>>>           hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> -    if (!ret)
>>> -        hba->is_sys_suspended = false;
>>> +
>>> +    hba->is_sys_suspended = false;
>>>       up(&hba->host_sem);
>>> -    return ret;
>>> +    return 0;
>>>   }
>>>   EXPORT_SYMBOL(ufshcd_system_resume);
>>>   @@ -9058,12 +9181,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
>>>    * @hba: per adapter instance
>>>    *
>>>    * Check the description of ufshcd_suspend() function for more details.
>>> + * Also check the description of __ufshcd_wl_suspend().
>>>    *
>>>    * Returns 0 for success and non-zero for failure
>>>    */
>>>   int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>>   {
>>> -    int ret = 0;
>>>       ktime_t start = ktime_get();
>>>         if (!hba)
>>> @@ -9072,12 +9195,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>>       if (!hba->is_powered)
>>>           goto out;
>>>       else
>>> -        ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
>>> +        ufshcd_suspend(hba);
>>>   out:
>>> -    trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
>>> +    trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
>>>           ktime_to_us(ktime_sub(ktime_get(), start)),
>>>           hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> -    return ret;
>>> +    return 0;
>>>   }
>>>   EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>>   @@ -9085,26 +9208,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>>    * ufshcd_runtime_resume - runtime resume routine
>>>    * @hba: per adapter instance
>>>    *
>>> - * This function basically brings the UFS device, UniPro link and controller
>>> + * This function basically brings controller
>>>    * to active state. Following operations are done in this function:
>>>    *
>>>    * 1. Turn on all the controller related clocks
>>> - * 2. Bring the UniPro link out of Hibernate state
>>> - * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
>>> - *    to active state.
>>> - * 4. If auto-bkops is enabled on the device, disable it.
>>> - *
>>> - * So following would be the possible power state after this function return
>>> - * successfully:
>>> - *    S1: UFS device in Active state with VCC rail ON
>>> - *        UniPro link in Active state
>>> - *        All the UFS/UniPro controller clocks are ON
>>> - *
>>> - * Returns 0 for success and non-zero for failure
>>> + * 2. Turn ON VCC rail
>>>    */
>>>   int ufshcd_runtime_resume(struct ufs_hba *hba)
>>>   {
>>> -    int ret = 0;
>>>       ktime_t start = ktime_get();
>>>         if (!hba)
>>> @@ -9113,12 +9224,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
>>>       if (!hba->is_powered)
>>>           goto out;
>>>       else
>>> -        ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
>>> +        ufshcd_resume(hba);
>>>   out:
>>> -    trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
>>> +    trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
>>>           ktime_to_us(ktime_sub(ktime_get(), start)),
>>>           hba->curr_dev_pwr_mode, hba->uic_link_state);
>>> -    return ret;
>>> +    return 0;
>>>   }
>>>   EXPORT_SYMBOL(ufshcd_runtime_resume);
>>>   @@ -9132,14 +9243,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
>>>    * ufshcd_shutdown - shutdown routine
>>>    * @hba: per adapter instance
>>>    *
>>> - * This function would power off both UFS device and UFS link.
>>> + * This function would turn off both UFS device and UFS hba
>>> + * regulators. It would also disable clocks.
>>>    *
>>>    * Returns 0 always to allow force shutdown even in case of errors.
>>>    */
>>>   int ufshcd_shutdown(struct ufs_hba *hba)
>>>   {
>>> -    int ret = 0;
>>> -
>>>       down(&hba->host_sem);
>>>       hba->shutting_down = true;
>>>       up(&hba->host_sem);
>>> @@ -9152,10 +9262,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>>>         pm_runtime_get_sync(hba->dev);
>>>   -    ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
>>> +    ufshcd_suspend(hba);
>>>   out:
>>> -    if (ret)
>>> -        dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
>>>       hba->is_powered = false;
>>>       /* allow force shutdown even in case of errors */
>>>       return 0;
>>> @@ -9477,15 +9585,163 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>>>   }
>>>   EXPORT_SYMBOL_GPL(ufshcd_init);
>>>   +void ufshcd_resume_complete(struct device *dev)
>>> +{
>>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>>> +
>>> +    pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
>>> +}
>>> +EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
>>> +
>>> +int ufshcd_suspend_prepare(struct device *dev)
>>> +{
>>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>>> +
>>> +    /*
>>> +     * SCSI assumes that runtime-pm and system-pm for scsi drivers
>>> +     * are same. And it doesn't wake up the device for system-suspend
>>> +     * if it's runtime suspended. But ufs doesn't follow that.
>>> +     * The rpm-lvl and spm-lvl can be different in ufs.
>>> +     * Force it to honor system-suspend.
>>> +     */
>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>> +    /* Refer ufshcd_resume_complete() */
>>> +    pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>> +    return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int ufshcd_wl_poweroff(struct device *dev)
>>> +{
>>> +    ufshcd_wl_shutdown(dev);
>>> +    return 0;
>>> +}
>>> +#endif
>>> +
>>> +static int ufshcd_wl_probe(struct device *dev)
>>> +{
>>> +    return is_device_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
>>
>> The "ufs_device_wlun" driver owns PM for sdev_ufs_device because it
>> provides the dev_pm_ops.  This is where the pm_runtime_allow() belongs
>> and it is symmetrical with the pm_runtime_forbid() in ufshcd_wl_remove().
>>
>>     if (!is_device_wlun(to_scsi_device(dev)))
>>         return -ENODEV;
>>     blk_pm_runtime_init(dev);
>>     pm_runtime_set_autosuspend_delay(dev, 0);
>>     pm_runtime_allow(dev);
>>
>> Note sdev_ufs_device will not runtime suspend here unless the
>> device links have been added and all consumers have suspended.
>> That is handled separately by the pm_runtime_get_noresume() in
>> ufshcd_slave_configure() and the pm_runtime_put() when luns_avail == 1
>> in ufshcd_setup_links().
>>
>>> +}
>>> +
>>> +static int ufshcd_wl_remove(struct device *dev)
>>> +{
>>> +    pm_runtime_forbid(dev);
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct dev_pm_ops ufshcd_wl_pm_ops = {
>>> +#ifdef CONFIG_PM_SLEEP
>>> +    .suspend = ufshcd_wl_suspend,
>>> +    .resume = ufshcd_wl_resume,
>>> +    .freeze = ufshcd_wl_suspend,
>>> +    .thaw = ufshcd_wl_resume,
>>> +    .poweroff = ufshcd_wl_poweroff,
>>> +    .restore = ufshcd_wl_resume,
>>> +#endif
>>> +    SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
>>> +};
>>> +
>>> +/**
>>> + * ufs_dev_wlun_template - describes ufs device wlun
>>> + * ufs-device wlun - used to send pm commands
>>> + * All luns are consumers of ufs-device wlun.
>>> + *
>>> + * Currently, no sd driver is present for wluns.
>>> + * Hence the no specific pm operations are performed.
>>> + * With ufs design, SSU should be sent to ufs-device wlun.
>>> + * Hence register a scsi driver for ufs wluns only.
>>> + */
>>> +static struct scsi_driver ufs_dev_wlun_template = {
>>> +    .gendrv = {
>>> +        .name = "ufs_device_wlun",
>>> +        .owner = THIS_MODULE,
>>> +        .probe = ufshcd_wl_probe,
>>> +        .remove = ufshcd_wl_remove,
>>> +        .pm = &ufshcd_wl_pm_ops,
>>> +        .shutdown = ufshcd_wl_shutdown,
>>> +    },
>>> +};
>>> +
>>> +static int ufshcd_rpmb_probe(struct device *dev)
>>> +{
>>> +    return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
>>> +}
>>> +
>>> +static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
>>> +{
>>> +    int ret = 0;
>>> +
>>> +    if (!hba->wlun_rpmb_clr_ua)
>>> +        return 0;
>>> +    ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
>>> +    if (!ret)
>>> +        hba->wlun_rpmb_clr_ua = 0;
>>> +    return ret;
>>> +}
>>> +
>>> +static int ufshcd_rpmb_runtime_resume(struct device *dev)
>>> +{
>>> +    struct ufs_hba *hba = wlun_dev_to_hba(dev);
>>> +
>>> +    if (hba->sdev_rpmb)
>>> +        return ufshcd_clear_rpmb_uac(hba);
>>> +    return 0;
>>> +}
>>> +
>>> +static int ufshcd_rpmb_resume(struct device *dev)
>>> +{
>>> +    struct ufs_hba *hba = wlun_dev_to_hba(dev);
>>> +
>>> +    if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
>>> +        return ufshcd_clear_rpmb_uac(hba);
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct dev_pm_ops ufs_rpmb_pm_ops = {
>>> +    SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
>>> +    SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
>>> +};
>>> +
>>> +/**
>>> + * Describes the ufs rpmb wlun.
>>> + * Used only to send uac.
>>> + */
>>> +static struct scsi_driver ufs_rpmb_wlun_template = {
>>> +    .gendrv = {
>>> +        .name = "ufs_rpmb_wlun",
>>> +        .owner = THIS_MODULE,
>>> +        .probe = ufshcd_rpmb_probe,
>>> +        .pm = &ufs_rpmb_pm_ops,
>>> +    },
>>> +};
>>> +
>>>   static int __init ufshcd_core_init(void)
>>>   {
>>> +    int ret;
>>> +
>>>       ufs_debugfs_init();
>>> +
>>> +    ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
>>> +    if (ret) {
>>> +        ufs_debugfs_exit();
>>> +        return ret;
>>> +    }
>>> +    ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
>>> +    if (ret) {
>>> +        ufs_debugfs_exit();
>>> +        scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>>> +        return ret;
>>> +    }
>>>       return 0;
>>>   }
>>>     static void __exit ufshcd_core_exit(void)
>>>   {
>>>       ufs_debugfs_exit();
>>> +    scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>>> +    scsi_unregister_driver(&ufs_rpmb_wlun_template.gendrv);
>>>   }
>>>     module_init(ufshcd_core_init);
>>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>>> index ee61f82..7841b2a 100644
>>> --- a/drivers/scsi/ufs/ufshcd.h
>>> +++ b/drivers/scsi/ufs/ufshcd.h
>>> @@ -72,6 +72,8 @@ enum ufs_event_type {
>>>       UFS_EVT_LINK_STARTUP_FAIL,
>>>       UFS_EVT_RESUME_ERR,
>>>       UFS_EVT_SUSPEND_ERR,
>>> +    UFS_EVT_WL_SUSP_ERR,
>>> +    UFS_EVT_WL_RES_ERR,
>>>         /* abnormal events */
>>>       UFS_EVT_DEV_RESET,
>>> @@ -804,6 +806,7 @@ struct ufs_hba {
>>>       struct list_head clk_list_head;
>>>         bool wlun_dev_clr_ua;
>>> +    bool wlun_rpmb_clr_ua;
>>>         /* Number of requests aborts */
>>>       int req_abort_count;
>>> @@ -841,6 +844,7 @@ struct ufs_hba {
>>>   #ifdef CONFIG_DEBUG_FS
>>>       struct dentry *debugfs_root;
>>>   #endif
>>> +    u32 luns_avail;
>>>   };
>>>     /* Returns true if clocks can be gated. Otherwise false */
>>> @@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
>>>                    enum query_opcode desc_op);
>>>     int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
>>> +int ufshcd_suspend_prepare(struct device *dev);
>>> +void ufshcd_resume_complete(struct device *dev);
>>>     /* Wrapper functions for safely calling variant operations */
>>>   static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
>>> diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
>>> index e151477..d9d233b 100644
>>> --- a/include/trace/events/ufs.h
>>> +++ b/include/trace/events/ufs.h
>>> @@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
>>>                 int dev_state, int link_state),
>>>            TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>   +DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>> +              int dev_state, int link_state),
>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>> +
>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>> +              int dev_state, int link_state),
>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>> +
>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>> +              int dev_state, int link_state),
>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>> +
>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>> +              int dev_state, int link_state),
>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>> +
>>>   TRACE_EVENT(ufshcd_command,
>>>       TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
>>>            unsigned int tag, u32 doorbell, int transfer_len, u32 intr,
>>>
>>
> 
> 

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das (asd)]

On 3/22/2021 11:12 PM, Adrian Hunter wrote:
> On 22/03/21 9:53 pm, Asutosh Das (asd) wrote:
>> On 3/19/2021 10:47 AM, Adrian Hunter wrote:
>>> On 19/03/21 2:35 am, Asutosh Das wrote:
>>>> During runtime-suspend of ufs host, the scsi devices are
>>>> already suspended and so are the queues associated with them.
>>>> But the ufs host sends SSU to wlun during its runtime-suspend.
>>>> During the process blk_queue_enter checks if the queue is not in
>>>> suspended state. If so, it waits for the queue to resume, and never
>>>> comes out of it.
>>>> The commit
>>>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>>>> adds the check if the queue is in suspended state in blk_queue_enter().
>>>>
>>>> Call trace:
>>>>    __switch_to+0x174/0x2c4
>>>>    __schedule+0x478/0x764
>>>>    schedule+0x9c/0xe0
>>>>    blk_queue_enter+0x158/0x228
>>>>    blk_mq_alloc_request+0x40/0xa4
>>>>    blk_get_request+0x2c/0x70
>>>>    __scsi_execute+0x60/0x1c4
>>>>    ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>>>    ufshcd_suspend+0x208/0x83c
>>>>    ufshcd_runtime_suspend+0x40/0x154
>>>>    ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>>>    pm_generic_runtime_suspend+0x28/0x3c
>>>>    __rpm_callback+0x80/0x2a4
>>>>    rpm_suspend+0x308/0x614
>>>>    rpm_idle+0x158/0x228
>>>>    pm_runtime_work+0x84/0xac
>>>>    process_one_work+0x1f0/0x470
>>>>    worker_thread+0x26c/0x4c8
>>>>    kthread+0x13c/0x320
>>>>    ret_from_fork+0x10/0x18
>>>>
>>>> Fix this by registering ufs device wlun as a scsi driver and
>>>> registering it for block runtime-pm. Also make this as a
>>>> supplier for all other luns. That way, this device wlun
>>>> suspends after all the consumers and resumes after
>>>> hba resumes.
>>>>
>>>> Co-developed-by: Can Guo <cang@codeaurora.org>
>>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>>>
>>> I have some more comments that may help straighten things out.
>>>
>>> Also please look at ufs_debugfs_get_user_access() and
>>> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
>>> sdev_ufs_device.
>>>
>>> It would also be good if you could re-base on linux-next.
>>>
>>
>> Hi Adrian
>> Thanks for the comments.
>>
>> I agree moving the code to wlun probe and other changes.
>> But it looks to me that it may not fully solve the issue.
>>
>> Please let me explain my understanding on this:
>>
>> (Please refer to the logs in v10)
>> scsi_autopm_*() are invoked on a sdev.
>> pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.
>>
>> For the device wlun:
>>      slave_configure():
>>          - doesn't set the rpm_autosuspend
>>          - pm_runtime_getnoresume()
>>      scsi_sysfs_add_sdev():
>>          - pm_runtime_forbid()
>>          - scsi_autopm_get_device()
>>          - device_add()
>>              - ufshcd_wl_probe()
>>          - scsi_autopm_put_device()
>>
>> For all other scsi devices:
>>      slave_alloc():
>>          - ufshcd_setup_links()
>> Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
> 
> With DL_FLAG_RPM_ACTIVE, links will 'get' not 'put'
> 
I'm referring to the pm_runtime_put(sdev_ufs_device) after all the links 
are setup, that you suggested to add.
>>      slave_configure():
>>          - set rpm_autosuspend
>>      scsi_sysfs_add_sdev():
>>          - scsi_autopm_get_device()
>>          - device_add() -> schedules an async probe()
>>          - scsi_autopm_put_device() - (1)
>>
>> Now the rpm_put_suppliers() can be invoked *after* pm_runtime_get_suppliers() of the async probe(), since both are running in different contexts.
> 
> Only if the sd device suspends.
> 
Correct. What'd stop the sd device from suspending?
We should be stopping the sd device from suspending here - imho.

>> In that case, the usage_count of supplier would be decremented until rpm_active of this link becomes 1.
> 
> Right, because the sd device suspended.
> 
>> Now the pm_runtime_get_suppliers() expects the link_active to be more than 1.
> 
> Not sure what you mean here. pm_runtime_*put*_suppliers() won't do anything if the link count is 1.
I'm referring to the logs that I pasted before:
[    6.941267][    T7] scsi 0:0:0:4: rpm_put_suppliers: [BEF] Supp 
(0:0:0:49488) usage_count: 4 rpm_active: 3

------ T196 Context comes in while T7 is running ----------
[    6.941466][  T196] scsi 0:0:0:4: pm_runtime_get_suppliers: 
(0:0:0:49488): supp: usage_count: 5 rpm_active: 4
--------------------------------------------------------------

[    7.788397][    T7] scsi 0:0:0:4: rpm_put_suppliers: [AFT] Supp 
(0:0:0:49488) usage_count: 2 rpm_active: 1

I meant to say that, if the rpm_put_suppliers() is invoked after the 
pm_runtime_get_suppliers() as is seen above then the link_active may 
become 1 even *after* pm_runtime_get_suppliers() is invoked.

I'm referring to the pm_runtime_get_suppliers() invoked from:
driver_probe_device() - say for, sd 0:0:0:x
	|- pm_runtime_get_suppliers() - for sd 0:0:0:49488
> 
>> Now then, there comes a time, that when sd_probe() schedules a suspend, the supplier usage_count becomes 0 and the link_active becomes 1.
>> And the supplier suspends before the consumer.
> 
> sd probe first resumes the sd device which will resume the supplier.
> 
Correct, but it'd again schedule a suspend (since autosuspend is enabled 
now) at the end of the sd_probe().
Thereafter, pm_runtime_put_suppliers()(sd 0:0:0:49488) is invoked from 
driver_probe_device() which had actually invoked sd_probe().
That'd make the link_active to 1 even when sd 0:0:0:x is active.

>>
>> So I was wondering, what'd make sure that the pm_runtime_get_suppliers() from driver_probe_device() is invoked after scsi_autopm_put_device() (1) finishes the rpm_put_suppliers().
>>
>> Am not sure if I'm missing something in this.
>> Do you think, the current changes alone can fix the above issue?
> 
> Yes, but let's see.
> 
Essentially, we should stop the sd device from runtime suspending until 
it's probe is done. Then allow the same. Does it make sense?
Please let me know what you think.

-asd

>>
>> -asd
>>
>>>> ---
>>>>    drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
>>>>    drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
>>>>    drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
>>>>    drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
>>>>    drivers/scsi/ufs/ufs-exynos.c      |   2 +
>>>>    drivers/scsi/ufs/ufs-hisi.c        |   2 +
>>>>    drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
>>>>    drivers/scsi/ufs/ufs-qcom.c        |   2 +
>>>>    drivers/scsi/ufs/ufs_bsg.c         |   6 +-
>>>>    drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
>>>>    drivers/scsi/ufs/ufshcd.c          | 622 ++++++++++++++++++++++++++-----------
>>>>    drivers/scsi/ufs/ufshcd.h          |   6 +
>>>>    include/trace/events/ufs.h         |  20 ++
>>>>    13 files changed, 491 insertions(+), 225 deletions(-)
>>>>
>>>> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
>>>> index 149391f..3e70c23 100644
>>>> --- a/drivers/scsi/ufs/cdns-pltfrm.c
>>>> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
>>>> @@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
>>>>        .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>>        .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>>        .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static struct platform_driver cdns_ufs_pltfrm_driver = {
>>>> diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>>> index 67a6a61..b01db12 100644
>>>> --- a/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>>> +++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c
>>>> @@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
>>>>        .runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
>>>>        .runtime_resume  = tc_dwc_g210_pci_runtime_resume,
>>>>        .runtime_idle    = tc_dwc_g210_pci_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {
>>>> diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
>>>> index dee98dc..06457d5 100644
>>>> --- a/drivers/scsi/ufs/ufs-debugfs.c
>>>> +++ b/drivers/scsi/ufs/ufs-debugfs.c
>>>> @@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
>>>>        ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
>>>>    }
>>>>    -void __exit ufs_debugfs_exit(void)
>>>> +void ufs_debugfs_exit(void)
>>>>    {
>>>>        debugfs_remove_recursive(ufs_debugfs_root);
>>>>    }
>>>> diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
>>>> index f35b39c..12c2730 100644
>>>> --- a/drivers/scsi/ufs/ufs-debugfs.h
>>>> +++ b/drivers/scsi/ufs/ufs-debugfs.h
>>>> @@ -9,7 +9,7 @@ struct ufs_hba;
>>>>      #ifdef CONFIG_DEBUG_FS
>>>>    void __init ufs_debugfs_init(void);
>>>> -void __exit ufs_debugfs_exit(void);
>>>> +void ufs_debugfs_exit(void);
>>>>    void ufs_debugfs_hba_init(struct ufs_hba *hba);
>>>>    void ufs_debugfs_hba_exit(struct ufs_hba *hba);
>>>>    #else
>>>> diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
>>>> index 267943a1..45c0b02 100644
>>>> --- a/drivers/scsi/ufs/ufs-exynos.c
>>>> +++ b/drivers/scsi/ufs/ufs-exynos.c
>>>> @@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
>>>>        .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>>        .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>>        .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static struct platform_driver exynos_ufs_pltform = {
>>>> diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
>>>> index 0aa5813..d463b44 100644
>>>> --- a/drivers/scsi/ufs/ufs-hisi.c
>>>> +++ b/drivers/scsi/ufs/ufs-hisi.c
>>>> @@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
>>>>        .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>>        .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>>        .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static struct platform_driver ufs_hisi_pltform = {
>>>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
>>>> index c55202b..51c82e3 100644
>>>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>>>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>>>> @@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
>>>>        /* enable unipro clock gating feature */
>>>>        ufs_mtk_cfg_unipro_cg(hba, true);
>>>>    -    /* configure auto-hibern8 timer to 10ms */
>>>> -    if (ufshcd_is_auto_hibern8_supported(hba)) {
>>>> -        ufshcd_auto_hibern8_update(hba,
>>>> -            FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>>>> -            FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
>>>> -    }
>>>> +    /* will be configured during probe hba */
>>>> +    if (ufshcd_is_auto_hibern8_supported(hba))
>>>> +        hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
>>>> +            FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
>>>>          ufs_mtk_setup_clk_gating(hba);
>>>>    @@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
>>>>        .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>>        .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>>        .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static struct platform_driver ufs_mtk_pltform = {
>>>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>>>> index f97d7b0..9aa098a 100644
>>>> --- a/drivers/scsi/ufs/ufs-qcom.c
>>>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>>>> @@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
>>>>        .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
>>>>        .runtime_resume  = ufshcd_pltfrm_runtime_resume,
>>>>        .runtime_idle    = ufshcd_pltfrm_runtime_idle,
>>>> +    .prepare     = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>>    };
>>>>      static struct platform_driver ufs_qcom_pltform = {
>>>> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
>>>> index 5b2bc1a..cbb5a90 100644
>>>> --- a/drivers/scsi/ufs/ufs_bsg.c
>>>> +++ b/drivers/scsi/ufs/ufs_bsg.c
>>>> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>>          bsg_reply->reply_payload_rcv_len = 0;
>>>>    -    pm_runtime_get_sync(hba->dev);
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>>          msgcode = bsg_request->msgcode;
>>>>        switch (msgcode) {
>>>> @@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>>            ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
>>>>                            &desc_len, desc_op);
>>>>            if (ret) {
>>>> -            pm_runtime_put_sync(hba->dev);
>>>> +            scsi_autopm_put_device(hba->sdev_ufs_device);
>>>>                goto out;
>>>>            }
>>>>    @@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
>>>>            break;
>>>>        }
>>>>    -    pm_runtime_put_sync(hba->dev);
>>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>>          if (!desc_buff)
>>>>            goto out;
>>>> diff --git a/drivers/scsi/ufs/ufshcd-pci.c b/drivers/scsi/ufs/ufshcd-pci.c
>>>> index fadd566..5d4ffd2 100644
>>>> --- a/drivers/scsi/ufs/ufshcd-pci.c
>>>> +++ b/drivers/scsi/ufs/ufshcd-pci.c
>>>> @@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
>>>>        return ufshcd_system_resume(dev_get_drvdata(dev));
>>>>    }
>>>>    -/**
>>>> - * ufshcd_pci_poweroff - suspend-to-disk poweroff function
>>>> - * @dev: pointer to PCI device handle
>>>> - *
>>>> - * Returns 0 if successful
>>>> - * Returns non-zero otherwise
>>>> - */
>>>> -static int ufshcd_pci_poweroff(struct device *dev)
>>>> -{
>>>> -    struct ufs_hba *hba = dev_get_drvdata(dev);
>>>> -    int spm_lvl = hba->spm_lvl;
>>>> -    int ret;
>>>> -
>>>> -    /*
>>>> -     * For poweroff we need to set the UFS device to PowerDown mode.
>>>> -     * Force spm_lvl to ensure that.
>>>> -     */
>>>> -    hba->spm_lvl = 5;
>>>> -    ret = ufshcd_system_suspend(hba);
>>>> -    hba->spm_lvl = spm_lvl;
>>>> -    return ret;
>>>> -}
>>>> -
>>>>    #endif /* !CONFIG_PM_SLEEP */
>>>>      #ifdef CONFIG_PM
>>>> @@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>>>    }
>>>>      static const struct dev_pm_ops ufshcd_pci_pm_ops = {
>>>> -#ifdef CONFIG_PM_SLEEP
>>>> -    .suspend    = ufshcd_pci_suspend,
>>>> -    .resume        = ufshcd_pci_resume,
>>>> -    .freeze        = ufshcd_pci_suspend,
>>>> -    .thaw        = ufshcd_pci_resume,
>>>> -    .poweroff    = ufshcd_pci_poweroff,
>>>> -    .restore    = ufshcd_pci_resume,
>>>> -#endif
>>>>        SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
>>>>                   ufshcd_pci_runtime_resume,
>>>>                   ufshcd_pci_runtime_idle)
>>>> +    SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
>>>> +#ifdef CONFIG_PM_SLEEP
>>>> +    .prepare    = ufshcd_suspend_prepare,
>>>> +    .complete    = ufshcd_resume_complete,
>>>> +#endif
>>>>    };
>>>>      static const struct pci_device_id ufshcd_pci_tbl[] = {
>>>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>>>> index 45624c7..7106cb8 100644
>>>> --- a/drivers/scsi/ufs/ufshcd.c
>>>> +++ b/drivers/scsi/ufs/ufshcd.c
>>>> @@ -16,6 +16,7 @@
>>>>    #include <linux/bitfield.h>
>>>>    #include <linux/blk-pm.h>
>>>>    #include <linux/blkdev.h>
>>>> +#include <scsi/scsi_driver.h>
>>>>    #include "ufshcd.h"
>>>>    #include "ufs_quirks.h"
>>>>    #include "unipro.h"
>>>> @@ -78,6 +79,8 @@
>>>>    /* Polling time to wait for fDeviceInit */
>>>>    #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
>>>>    +#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
>>>> +
>>>>    #define ufshcd_toggle_vreg(_dev, _vreg, _on)                \
>>>>        ({                                                              \
>>>>            int _ret;                                               \
>>>> @@ -1556,7 +1559,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>>>        if (value == hba->clk_scaling.is_enabled)
>>>>            goto out;
>>>>    -    pm_runtime_get_sync(hba->dev);
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>>        ufshcd_hold(hba, false);
>>>>          hba->clk_scaling.is_enabled = value;
>>>> @@ -1572,7 +1575,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
>>>>        }
>>>>          ufshcd_release(hba);
>>>> -    pm_runtime_put_sync(hba->dev);
>>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>>    out:
>>>>        up(&hba->host_sem);
>>>>        return err ? err : count;
>>>> @@ -2572,6 +2575,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
>>>>        return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
>>>>    }
>>>>    +static inline bool is_rpmb_wlun(struct scsi_device *sdev)
>>>> +{
>>>> +    return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
>>>> +}
>>>> +
>>>> +static inline bool is_device_wlun(struct scsi_device *sdev)
>>>> +{
>>>> +    return (sdev->lun ==
>>>> +        ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
>>>> +}
>>>> +
>>>>    static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
>>>>    {
>>>>        struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
>>>> @@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
>>>>        spin_unlock_irqrestore(hba->host->host_lock, flags);
>>>>          if (update && !pm_runtime_suspended(hba->dev)) {
>>>> -        pm_runtime_get_sync(hba->dev);
>>>> +        scsi_autopm_get_device(hba->sdev_ufs_device);
>>>>            ufshcd_hold(hba, false);
>>>>            ufshcd_auto_hibern8_enable(hba);
>>>>            ufshcd_release(hba);
>>>> -        pm_runtime_put(hba->dev);
>>>> +        scsi_autopm_put_device(hba->sdev_ufs_device);
>>>>        }
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
>>>> @@ -4808,6 +4822,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
>>>>    }
>>>>      /**
>>>> + * ufshcd_setup_links - associate link b/w device wlun and other luns
>>>> + * @sdev: pointer to SCSI device
>>>> + * @hba: pointer to ufs hba
>>>> + */
>>>> +static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
>>>> +{
>>>> +    struct device_link *link;
>>>> +
>>>> +    /*
>>>> +     * device wlun is the supplier & rest of the luns are consumers
>>>> +     * This ensures that device wlun suspends after all other luns.
>>>> +     */
>>>> +    if (hba->sdev_ufs_device) {
>>>> +        link = device_link_add(&sdev->sdev_gendev,
>>>> +                       &hba->sdev_ufs_device->sdev_gendev,
>>>> +                       DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
>>>> +        if (!link) {
>>>> +            dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
>>>> +                dev_name(&hba->sdev_ufs_device->sdev_gendev));
>>>> +            return;
>>>> +        }
>>>> +        hba->luns_avail--;
>>>> +        /* Ignore REPORT_LUN wlun probing */
>>>> +        if (hba->luns_avail != 1) {
>>>
>>> The condition here is the wrong way around. i.e. should be
>>>
>>>          if (hba->luns_avail == 1) {
>>>
>>>> +            pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
>>>
>>> If the usage_count is zero here, then we should let it suspend i.e. make this:
>>>
>>>              pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>>
>>> Note this pairs with the pm_runtime_get_noresume() that needs to be added
>>> to ufshcd_slave_configure.  Please see comments for ufshcd_slave_configure().
>>>
>>>
>>>> +            pm_runtime_allow(&hba->sdev_ufs_device->sdev_gendev);
>>>
>>> This pm_runtime_allow should not be here.  It should be in ufshcd_wl_probe().
>>> Please see comments for ufshcd_wl_probe().
>>>
>>>> +            return;
>>>> +        }
>>>> +    } else {
>>>> +        /* device wlun is probed */
>>>> +        hba->luns_avail--;
>>>> +    }
>>>> +}
>>>> +
>>>> +/**
>>>>     * ufshcd_slave_alloc - handle initial SCSI device configurations
>>>>     * @sdev: pointer to SCSI device
>>>>     *
>>>> @@ -4838,6 +4887,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
>>>>          ufshcd_get_lu_power_on_wp_status(hba, sdev);
>>>>    +    ufshcd_setup_links(hba, sdev);
>>>> +
>>>>        return 0;
>>>>    }
>>>>    @@ -4869,8 +4920,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
>>>>        blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
>>>>        if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
>>>>            blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
>>>> -
>>>> -    if (ufshcd_is_rpm_autosuspend_allowed(hba))
>>>> +    /*
>>>> +     * Block runtime-pm until all consumers are added.
>>>> +     * Refer ufshcd_setup_links().
>>>> +     */
>>>> +    if (is_device_wlun(sdev))
>>>> +        pm_runtime_forbid(&sdev->sdev_gendev);
>>>
>>> Since rpm_autosuspend is not being set for sdev_ufs_device, scsi_sysfs_add_sdev()
>>> will pm_runtime_forbid() it anyway.  We should increase the usage_count instead
>>> i.e.
>>>
>>>          pm_runtime_get_noresume(&sdev->sdev_gendev);
>>>
>>>> +    else if (ufshcd_is_rpm_autosuspend_allowed(hba))
>>>>            sdev->rpm_autosuspend = 1;
>>>>          ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
>>>> @@ -4985,15 +5041,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>>>>                 * UFS device needs urgent BKOPs.
>>>>                 */
>>>>                if (!hba->pm_op_in_progress &&
>>>> -                ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
>>>> -                schedule_work(&hba->eeh_work)) {
>>>> -                /*
>>>> -                 * Prevent suspend once eeh_work is scheduled
>>>> -                 * to avoid deadlock between ufshcd_suspend
>>>> -                 * and exception event handler.
>>>> -                 */
>>>> -                pm_runtime_get_noresume(hba->dev);
>>>> -            }
>>>> +                ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
>>>> +                /* Flushed in suspend */
>>>> +                schedule_work(&hba->eeh_work);
>>>>                break;
>>>>            case UPIU_TRANSACTION_REJECT_UPIU:
>>>>                /* TODO: handle Reject UPIU Response */
>>>> @@ -5589,8 +5639,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
>>>>         * after a certain delay to recheck the threshold by next runtime
>>>>         * suspend.
>>>>         */
>>>> -    pm_runtime_get_sync(hba->dev);
>>>> -    pm_runtime_put_sync(hba->dev);
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>>    }
>>>>      /**
>>>> @@ -5607,7 +5657,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>>>        u32 status = 0;
>>>>        hba = container_of(work, struct ufs_hba, eeh_work);
>>>>    -    pm_runtime_get_sync(hba->dev);
>>>>        ufshcd_scsi_block_requests(hba);
>>>>        err = ufshcd_get_ee_status(hba, &status);
>>>>        if (err) {
>>>> @@ -5623,14 +5672,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>>>>      out:
>>>>        ufshcd_scsi_unblock_requests(hba);
>>>> -    /*
>>>> -     * pm_runtime_get_noresume is called while scheduling
>>>> -     * eeh_work to avoid suspend racing with exception work.
>>>> -     * Hence decrement usage counter using pm_runtime_put_noidle
>>>> -     * to allow suspend on completion of exception event handler.
>>>> -     */
>>>> -    pm_runtime_put_noidle(hba->dev);
>>>> -    pm_runtime_put(hba->dev);
>>>>        return;
>>>>    }
>>>>    @@ -5755,12 +5796,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
>>>>      static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
>>>>    {
>>>> -    pm_runtime_get_sync(hba->dev);
>>>> -    if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>> +    if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
>>>> +        hba->is_sys_suspended) {
>>>>            enum ufs_pm_op pm_op;
>>>>              /*
>>>> -         * Don't assume anything of pm_runtime_get_sync(), if
>>>> +         * Don't assume anything of resume, if
>>>>             * resume fails, irq and clocks can be OFF, and powers
>>>>             * can be OFF or in LPM.
>>>>             */
>>>> @@ -5789,7 +5831,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
>>>>        ufshcd_release(hba);
>>>>        if (ufshcd_is_clkscaling_supported(hba))
>>>>            ufshcd_clk_scaling_suspend(hba, false);
>>>> -    pm_runtime_put(hba->dev);
>>>> +    pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>>>    }
>>>>      static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
>>>> @@ -5810,14 +5852,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
>>>>          hba->is_sys_suspended = false;
>>>>        /*
>>>> -     * Set RPM status of hba device to RPM_ACTIVE,
>>>> +     * Set RPM status of wlun device to RPM_ACTIVE,
>>>>         * this also clears its runtime error.
>>>>         */
>>>> -    ret = pm_runtime_set_active(hba->dev);
>>>> +    ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
>>>>        /*
>>>> -     * If hba device had runtime error, we also need to resume those
>>>> -     * scsi devices under hba in case any of them has failed to be
>>>> -     * resumed due to hba runtime resume failure. This is to unblock
>>>> +     * If wlun device had runtime error, we also need to resume those
>>>> +     * consumer scsi devices in case any of them has failed to be
>>>> +     * resumed due to supplier runtime resume failure. This is to unblock
>>>>         * blk_queue_enter in case there are bios waiting inside it.
>>>>         */
>>>>        if (!ret) {
>>>> @@ -7207,11 +7249,12 @@ static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
>>>>      static inline void ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
>>>>    {
>>>> +    int dly = is_device_wlun(sdev) ? 0:RPM_AUTOSUSPEND_DELAY_MS;
>>>> +
>>>>        scsi_autopm_get_device(sdev);
>>>>        blk_pm_runtime_init(sdev->request_queue, &sdev->sdev_gendev);
>>>>        if (sdev->rpm_autosuspend)
>>>> -        pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev,
>>>> -                         RPM_AUTOSUSPEND_DELAY_MS);
>>>> +        pm_runtime_set_autosuspend_delay(&sdev->sdev_gendev, dly);
>>>>        scsi_autopm_put_device(sdev);
>>>>    }
>>>>    @@ -7253,6 +7296,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>>>>            hba->sdev_ufs_device = NULL;
>>>>            goto out;
>>>>        }
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>>        ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
>>>
>>> Let's drop both scsi_autopm_get_device() and ufshcd_blk_pm_runtime_init()
>>> here and instead do things in ufshcd_wl_probe() - see comments for ufshcd_wl_probe()
>>>
>>>>        scsi_device_put(hba->sdev_ufs_device);
>>>>    @@ -7417,6 +7461,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>>>>            goto out;
>>>>        }
>>>>    +    hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
>>>> +        desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
>>>> +
>>>>        ufs_fixup_device_setup(hba);
>>>>          ufshcd_wb_probe(hba, desc_buf);
>>>> @@ -7892,6 +7939,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
>>>>        ufshcd_set_ufs_dev_active(hba);
>>>>        ufshcd_force_reset_auto_bkops(hba);
>>>>        hba->wlun_dev_clr_ua = true;
>>>> +    hba->wlun_rpmb_clr_ua = true;
>>>>          /* Gear up to HS gear if supported */
>>>>        if (hba->max_pwr_info.is_valid) {
>>>> @@ -8475,7 +8523,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
>>>>         * handling context.
>>>>         */
>>>>        hba->host->eh_noresume = 1;
>>>> -    ufshcd_clear_ua_wluns(hba);
>>>> +    if (hba->wlun_dev_clr_ua)
>>>> +        ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
>>>>          cmd[4] = pwr_mode << 4;
>>>>    @@ -8650,23 +8699,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
>>>>            ufshcd_setup_hba_vreg(hba, true);
>>>>    }
>>>>    -/**
>>>> - * ufshcd_suspend - helper function for suspend operations
>>>> - * @hba: per adapter instance
>>>> - * @pm_op: desired low power operation type
>>>> - *
>>>> - * This function will try to put the UFS device and link into low power
>>>> - * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
>>>> - * (System PM level).
>>>> - *
>>>> - * If this function is called during shutdown, it will make sure that
>>>> - * both UFS device and UFS link is powered off.
>>>> - *
>>>> - * NOTE: UFS device & link must be active before we enter in this function.
>>>> - *
>>>> - * Returns 0 for success and non-zero for failure
>>>> - */
>>>> -static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>> +static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>    {
>>>>        int ret = 0;
>>>>        int check_for_bkops;
>>>> @@ -8674,7 +8707,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>        enum ufs_dev_pwr_mode req_dev_pwr_mode;
>>>>        enum uic_link_state req_link_state;
>>>>    -    hba->pm_op_in_progress = 1;
>>>> +    hba->pm_op_in_progress = true;
>>>>        if (!ufshcd_is_shutdown_pm(pm_op)) {
>>>>            pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
>>>>                 hba->rpm_lvl : hba->spm_lvl;
>>>> @@ -8697,17 +8730,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>          if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
>>>>                req_link_state == UIC_LINK_ACTIVE_STATE) {
>>>> -        goto disable_clks;
>>>> +        goto enable_scaling;
>>>>        }
>>>>          if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
>>>>            (req_link_state == hba->uic_link_state))
>>>> -        goto enable_gating;
>>>> +        goto enable_scaling;
>>>>          /* UFS device & link must be active before we enter in this function */
>>>>        if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
>>>>            ret = -EINVAL;
>>>> -        goto enable_gating;
>>>> +        goto enable_scaling;
>>>>        }
>>>>          if (ufshcd_is_runtime_pm(pm_op)) {
>>>> @@ -8719,7 +8752,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>                 */
>>>>                ret = ufshcd_urgent_bkops(hba);
>>>>                if (ret)
>>>> -                goto enable_gating;
>>>> +                goto enable_scaling;
>>>>            } else {
>>>>                /* make sure that auto bkops is disabled */
>>>>                ufshcd_disable_auto_bkops(hba);
>>>> @@ -8747,7 +8780,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>            if (!hba->dev_info.b_rpm_dev_flush_capable) {
>>>>                ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
>>>>                if (ret)
>>>> -                goto enable_gating;
>>>> +                goto enable_scaling;
>>>>            }
>>>>        }
>>>>    @@ -8760,7 +8793,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>        if (ret)
>>>>            goto set_dev_active;
>>>>    -disable_clks:
>>>>        /*
>>>>         * Call vendor specific suspend callback. As these callbacks may access
>>>>         * vendor specific host controller register space call them before the
>>>> @@ -8769,28 +8801,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>        ret = ufshcd_vops_suspend(hba, pm_op);
>>>>        if (ret)
>>>>            goto set_link_active;
>>>> -    /*
>>>> -     * Disable the host irq as host controller as there won't be any
>>>> -     * host controller transaction expected till resume.
>>>> -     */
>>>> -    ufshcd_disable_irq(hba);
>>>> -
>>>> -    ufshcd_setup_clocks(hba, false);
>>>> -
>>>> -    if (ufshcd_is_clkgating_allowed(hba)) {
>>>> -        hba->clk_gating.state = CLKS_OFF;
>>>> -        trace_ufshcd_clk_gating(dev_name(hba->dev),
>>>> -                    hba->clk_gating.state);
>>>> -    }
>>>> -
>>>> -    ufshcd_vreg_set_lpm(hba);
>>>> -
>>>> -    /* Put the host controller in low power mode if possible */
>>>> -    ufshcd_hba_vreg_set_lpm(hba);
>>>>        goto out;
>>>>      set_link_active:
>>>> -    ufshcd_vreg_set_hpm(hba);
>>>>        /*
>>>>         * Device hardware reset is required to exit DeepSleep. Also, for
>>>>         * DeepSleep, the link is off so host reset and restore will be done
>>>> @@ -8812,57 +8825,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>        }
>>>>        if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
>>>>            ufshcd_disable_auto_bkops(hba);
>>>> -enable_gating:
>>>> +enable_scaling:
>>>>        if (ufshcd_is_clkscaling_supported(hba))
>>>>            ufshcd_clk_scaling_suspend(hba, false);
>>>>    -    hba->clk_gating.is_suspended = false;
>>>>        hba->dev_info.b_rpm_dev_flush_capable = false;
>>>> -    ufshcd_clear_ua_wluns(hba);
>>>> -    ufshcd_release(hba);
>>>>    out:
>>>>        if (hba->dev_info.b_rpm_dev_flush_capable) {
>>>>            schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
>>>>                msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
>>>>        }
>>>>    -    hba->pm_op_in_progress = 0;
>>>> -
>>>> -    if (ret)
>>>> -        ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
>>>> +    if (ret) {
>>>> +        ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
>>>> +        hba->clk_gating.is_suspended = false;
>>>> +        ufshcd_release(hba);
>>>> +    }
>>>> +    hba->pm_op_in_progress = false;
>>>>        return ret;
>>>>    }
>>>>    -/**
>>>> - * ufshcd_resume - helper function for resume operations
>>>> - * @hba: per adapter instance
>>>> - * @pm_op: runtime PM or system PM
>>>> - *
>>>> - * This function basically brings the UFS device, UniPro link and controller
>>>> - * to active state.
>>>> - *
>>>> - * Returns 0 for success and non-zero for failure
>>>> - */
>>>> -static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>> +static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>    {
>>>>        int ret;
>>>> -    enum uic_link_state old_link_state;
>>>> +    enum uic_link_state old_link_state = hba->uic_link_state;
>>>>    -    hba->pm_op_in_progress = 1;
>>>> -    old_link_state = hba->uic_link_state;
>>>> -
>>>> -    ufshcd_hba_vreg_set_hpm(hba);
>>>> -    ret = ufshcd_vreg_set_hpm(hba);
>>>> -    if (ret)
>>>> -        goto out;
>>>> -
>>>> -    /* Make sure clocks are enabled before accessing controller */
>>>> -    ret = ufshcd_setup_clocks(hba, true);
>>>> -    if (ret)
>>>> -        goto disable_vreg;
>>>> -
>>>> -    /* enable the host irq as host controller would be active soon */
>>>> -    ufshcd_enable_irq(hba);
>>>> +    hba->pm_op_in_progress = true;
>>>>          /*
>>>>         * Call vendor specific resume callback. As these callbacks may access
>>>> @@ -8871,7 +8859,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>         */
>>>>        ret = ufshcd_vops_resume(hba, pm_op);
>>>>        if (ret)
>>>> -        goto disable_irq_and_vops_clks;
>>>> +        goto out;
>>>>          /* For DeepSleep, the only supported option is to have the link off */
>>>>        WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
>>>> @@ -8916,31 +8904,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>             */
>>>>            ufshcd_urgent_bkops(hba);
>>>>    -    hba->clk_gating.is_suspended = false;
>>>> -
>>>> -    if (ufshcd_is_clkscaling_supported(hba))
>>>> -        ufshcd_clk_scaling_suspend(hba, false);
>>>> -
>>>> -    /* Enable Auto-Hibernate if configured */
>>>> -    ufshcd_auto_hibern8_enable(hba);
>>>> +    if (hba->clk_scaling.is_allowed)
>>>> +        ufshcd_resume_clkscaling(hba);
>>>>          if (hba->dev_info.b_rpm_dev_flush_capable) {
>>>>            hba->dev_info.b_rpm_dev_flush_capable = false;
>>>>            cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
>>>>        }
>>>>    -    ufshcd_clear_ua_wluns(hba);
>>>> -
>>>> -    /* Schedule clock gating in case of no access to UFS device yet */
>>>> -    ufshcd_release(hba);
>>>> -
>>>> +    /* Enable Auto-Hibernate if configured */
>>>> +    ufshcd_auto_hibern8_enable(hba);
>>>>        goto out;
>>>>      set_old_link_state:
>>>>        ufshcd_link_state_transition(hba, old_link_state, 0);
>>>>    vendor_suspend:
>>>>        ufshcd_vops_suspend(hba, pm_op);
>>>> -disable_irq_and_vops_clks:
>>>> +out:
>>>> +    if (ret)
>>>> +        ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
>>>> +    hba->clk_gating.is_suspended = false;
>>>> +    ufshcd_release(hba);
>>>> +    hba->pm_op_in_progress = false;
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int ufshcd_wl_runtime_suspend(struct device *dev)
>>>> +{
>>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>>> +    struct ufs_hba *hba;
>>>> +    int ret;
>>>> +    ktime_t start = ktime_get();
>>>> +
>>>> +    hba = shost_priv(sdev->host);
>>>> +
>>>> +    ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
>>>> +    if (ret)
>>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>>> +
>>>> +    trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
>>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int ufshcd_wl_runtime_resume(struct device *dev)
>>>> +{
>>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>>> +    struct ufs_hba *hba;
>>>> +    int ret = 0;
>>>> +    ktime_t start = ktime_get();
>>>> +
>>>> +    hba = shost_priv(sdev->host);
>>>> +
>>>> +    ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
>>>> +    if (ret)
>>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>>> +
>>>> +    trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
>>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +#ifdef CONFIG_PM_SLEEP
>>>> +static int ufshcd_wl_suspend(struct device *dev)
>>>> +{
>>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>>> +    struct ufs_hba *hba;
>>>> +    int ret;
>>>> +    ktime_t start = ktime_get();
>>>> +
>>>> +    hba = shost_priv(sdev->host);
>>>> +    ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
>>>> +    if (ret)
>>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__,  ret);
>>>> +
>>>> +    trace_ufshcd_wl_suspend(dev_name(dev), ret,
>>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int ufshcd_wl_resume(struct device *dev)
>>>> +{
>>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>>> +    struct ufs_hba *hba;
>>>> +    int ret = 0;
>>>> +    ktime_t start = ktime_get();
>>>> +
>>>> +    if (pm_runtime_suspended(dev))
>>>> +        return 0;
>>>> +    hba = shost_priv(sdev->host);
>>>> +
>>>> +    ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
>>>> +    if (ret)
>>>> +        dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
>>>> +
>>>> +    trace_ufshcd_wl_resume(dev_name(dev), ret,
>>>> +        ktime_to_us(ktime_sub(ktime_get(), start)),
>>>> +        hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +#endif
>>>> +
>>>> +static void ufshcd_wl_shutdown(struct device *dev)
>>>> +{
>>>> +    struct scsi_device *sdev = to_scsi_device(dev);
>>>> +    struct ufs_hba *hba;
>>>> +
>>>> +    hba = shost_priv(sdev->host);
>>>> +    /* Turn on everything while shutting down */
>>>> +    scsi_autopm_get_device(sdev);
>>>> +    scsi_device_quiesce(sdev);
>>>> +    shost_for_each_device(sdev, hba->host) {
>>>> +        if (sdev == hba->sdev_ufs_device)
>>>> +            continue;
>>>> +        scsi_device_quiesce(sdev);
>>>> +    }
>>>> +    __ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
>>>> +}
>>>> +
>>>> +/**
>>>> + * ufshcd_suspend - helper function for suspend operations
>>>> + * @hba: per adapter instance
>>>> + *
>>>> + * This function will put disable irqs, turn off clocks
>>>> + * and set vreg and hba-vreg in lpm mode.
>>>> + * Also check the description of __ufshcd_wl_suspend().
>>>> + */
>>>> +static void ufshcd_suspend(struct ufs_hba *hba)
>>>> +{
>>>> +    hba->pm_op_in_progress = 1;
>>>> +
>>>> +    /*
>>>> +     * Disable the host irq as host controller as there won't be any
>>>> +     * host controller transaction expected till resume.
>>>> +     */
>>>>        ufshcd_disable_irq(hba);
>>>>        ufshcd_setup_clocks(hba, false);
>>>>        if (ufshcd_is_clkgating_allowed(hba)) {
>>>> @@ -8948,6 +9052,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>            trace_ufshcd_clk_gating(dev_name(hba->dev),
>>>>                        hba->clk_gating.state);
>>>>        }
>>>> +
>>>> +    ufshcd_vreg_set_lpm(hba);
>>>> +    /* Put the host controller in low power mode if possible */
>>>> +    ufshcd_hba_vreg_set_lpm(hba);
>>>> +    hba->pm_op_in_progress = 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * ufshcd_resume - helper function for resume operations
>>>> + * @hba: per adapter instance
>>>> + *
>>>> + * This function basically turns on the regulators, clocks and
>>>> + * irqs of the hba.
>>>> + * Also check the description of __ufshcd_wl_resume().
>>>> + *
>>>> + * Returns 0 for success and non-zero for failure
>>>> + */
>>>> +static int ufshcd_resume(struct ufs_hba *hba)
>>>> +{
>>>> +    int ret;
>>>> +
>>>> +    hba->pm_op_in_progress = 1;
>>>> +
>>>> +    ufshcd_hba_vreg_set_hpm(hba);
>>>> +    ret = ufshcd_vreg_set_hpm(hba);
>>>> +    if (ret)
>>>> +        goto out;
>>>> +
>>>> +    /* Make sure clocks are enabled before accessing controller */
>>>> +    ret = ufshcd_setup_clocks(hba, true);
>>>> +    if (ret)
>>>> +        goto disable_vreg;
>>>> +
>>>> +    /* enable the host irq as host controller would be active soon */
>>>> +    ufshcd_enable_irq(hba);
>>>> +    goto out;
>>>> +
>>>>    disable_vreg:
>>>>        ufshcd_vreg_set_lpm(hba);
>>>>    out:
>>>> @@ -8962,6 +9103,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>>>     * @hba: per adapter instance
>>>>     *
>>>>     * Check the description of ufshcd_suspend() function for more details.
>>>> + * Also check the description of __ufshcd_wl_suspend().
>>>>     *
>>>>     * Returns 0 for success and non-zero for failure
>>>>     */
>>>> @@ -8987,21 +9129,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
>>>>             !hba->dev_info.b_rpm_dev_flush_capable)
>>>>            goto out;
>>>>    -    if (pm_runtime_suspended(hba->dev)) {
>>>> -        /*
>>>> -         * UFS device and/or UFS link low power states during runtime
>>>> -         * suspend seems to be different than what is expected during
>>>> -         * system suspend. Hence runtime resume the devic & link and
>>>> -         * let the system suspend low power states to take effect.
>>>> -         * TODO: If resume takes longer time, we might have optimize
>>>> -         * it in future by not resuming everything if possible.
>>>> -         */
>>>> -        ret = ufshcd_runtime_resume(hba);
>>>> -        if (ret)
>>>> -            goto out;
>>>> -    }
>>>> -
>>>> -    ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
>>>> +    ufshcd_suspend(hba);
>>>>    out:
>>>>        trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
>>>>            ktime_to_us(ktime_sub(ktime_get(), start)),
>>>> @@ -9023,7 +9151,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
>>>>      int ufshcd_system_resume(struct ufs_hba *hba)
>>>>    {
>>>> -    int ret = 0;
>>>>        ktime_t start = ktime_get();
>>>>          if (!hba)
>>>> @@ -9034,22 +9161,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
>>>>            down(&hba->host_sem);
>>>>        }
>>>>    -    if (!hba->is_powered || pm_runtime_suspended(hba->dev))
>>>> -        /*
>>>> -         * Let the runtime resume take care of resuming
>>>> -         * if runtime suspended.
>>>> -         */
>>>> +    if (!hba->is_powered)
>>>>            goto out;
>>>>        else
>>>> -        ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
>>>> +        ufshcd_resume(hba);
>>>>    out:
>>>> -    trace_ufshcd_system_resume(dev_name(hba->dev), ret,
>>>> +    trace_ufshcd_system_resume(dev_name(hba->dev), 0,
>>>>            ktime_to_us(ktime_sub(ktime_get(), start)),
>>>>            hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> -    if (!ret)
>>>> -        hba->is_sys_suspended = false;
>>>> +
>>>> +    hba->is_sys_suspended = false;
>>>>        up(&hba->host_sem);
>>>> -    return ret;
>>>> +    return 0;
>>>>    }
>>>>    EXPORT_SYMBOL(ufshcd_system_resume);
>>>>    @@ -9058,12 +9181,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
>>>>     * @hba: per adapter instance
>>>>     *
>>>>     * Check the description of ufshcd_suspend() function for more details.
>>>> + * Also check the description of __ufshcd_wl_suspend().
>>>>     *
>>>>     * Returns 0 for success and non-zero for failure
>>>>     */
>>>>    int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>>>    {
>>>> -    int ret = 0;
>>>>        ktime_t start = ktime_get();
>>>>          if (!hba)
>>>> @@ -9072,12 +9195,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
>>>>        if (!hba->is_powered)
>>>>            goto out;
>>>>        else
>>>> -        ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
>>>> +        ufshcd_suspend(hba);
>>>>    out:
>>>> -    trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
>>>> +    trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
>>>>            ktime_to_us(ktime_sub(ktime_get(), start)),
>>>>            hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> -    return ret;
>>>> +    return 0;
>>>>    }
>>>>    EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>>>    @@ -9085,26 +9208,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
>>>>     * ufshcd_runtime_resume - runtime resume routine
>>>>     * @hba: per adapter instance
>>>>     *
>>>> - * This function basically brings the UFS device, UniPro link and controller
>>>> + * This function basically brings controller
>>>>     * to active state. Following operations are done in this function:
>>>>     *
>>>>     * 1. Turn on all the controller related clocks
>>>> - * 2. Bring the UniPro link out of Hibernate state
>>>> - * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
>>>> - *    to active state.
>>>> - * 4. If auto-bkops is enabled on the device, disable it.
>>>> - *
>>>> - * So following would be the possible power state after this function return
>>>> - * successfully:
>>>> - *    S1: UFS device in Active state with VCC rail ON
>>>> - *        UniPro link in Active state
>>>> - *        All the UFS/UniPro controller clocks are ON
>>>> - *
>>>> - * Returns 0 for success and non-zero for failure
>>>> + * 2. Turn ON VCC rail
>>>>     */
>>>>    int ufshcd_runtime_resume(struct ufs_hba *hba)
>>>>    {
>>>> -    int ret = 0;
>>>>        ktime_t start = ktime_get();
>>>>          if (!hba)
>>>> @@ -9113,12 +9224,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
>>>>        if (!hba->is_powered)
>>>>            goto out;
>>>>        else
>>>> -        ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
>>>> +        ufshcd_resume(hba);
>>>>    out:
>>>> -    trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
>>>> +    trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
>>>>            ktime_to_us(ktime_sub(ktime_get(), start)),
>>>>            hba->curr_dev_pwr_mode, hba->uic_link_state);
>>>> -    return ret;
>>>> +    return 0;
>>>>    }
>>>>    EXPORT_SYMBOL(ufshcd_runtime_resume);
>>>>    @@ -9132,14 +9243,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
>>>>     * ufshcd_shutdown - shutdown routine
>>>>     * @hba: per adapter instance
>>>>     *
>>>> - * This function would power off both UFS device and UFS link.
>>>> + * This function would turn off both UFS device and UFS hba
>>>> + * regulators. It would also disable clocks.
>>>>     *
>>>>     * Returns 0 always to allow force shutdown even in case of errors.
>>>>     */
>>>>    int ufshcd_shutdown(struct ufs_hba *hba)
>>>>    {
>>>> -    int ret = 0;
>>>> -
>>>>        down(&hba->host_sem);
>>>>        hba->shutting_down = true;
>>>>        up(&hba->host_sem);
>>>> @@ -9152,10 +9262,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>>>>          pm_runtime_get_sync(hba->dev);
>>>>    -    ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
>>>> +    ufshcd_suspend(hba);
>>>>    out:
>>>> -    if (ret)
>>>> -        dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
>>>>        hba->is_powered = false;
>>>>        /* allow force shutdown even in case of errors */
>>>>        return 0;
>>>> @@ -9477,15 +9585,163 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(ufshcd_init);
>>>>    +void ufshcd_resume_complete(struct device *dev)
>>>> +{
>>>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>>>> +
>>>> +    pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
>>>> +
>>>> +int ufshcd_suspend_prepare(struct device *dev)
>>>> +{
>>>> +    struct ufs_hba *hba = dev_get_drvdata(dev);
>>>> +
>>>> +    /*
>>>> +     * SCSI assumes that runtime-pm and system-pm for scsi drivers
>>>> +     * are same. And it doesn't wake up the device for system-suspend
>>>> +     * if it's runtime suspended. But ufs doesn't follow that.
>>>> +     * The rpm-lvl and spm-lvl can be different in ufs.
>>>> +     * Force it to honor system-suspend.
>>>> +     */
>>>> +    scsi_autopm_get_device(hba->sdev_ufs_device);
>>>> +    /* Refer ufshcd_resume_complete() */
>>>> +    pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
>>>> +    scsi_autopm_put_device(hba->sdev_ufs_device);
>>>> +    return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
>>>> +
>>>> +#ifdef CONFIG_PM_SLEEP
>>>> +static int ufshcd_wl_poweroff(struct device *dev)
>>>> +{
>>>> +    ufshcd_wl_shutdown(dev);
>>>> +    return 0;
>>>> +}
>>>> +#endif
>>>> +
>>>> +static int ufshcd_wl_probe(struct device *dev)
>>>> +{
>>>> +    return is_device_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
>>>
>>> The "ufs_device_wlun" driver owns PM for sdev_ufs_device because it
>>> provides the dev_pm_ops.  This is where the pm_runtime_allow() belongs
>>> and it is symmetrical with the pm_runtime_forbid() in ufshcd_wl_remove().
>>>
>>>      if (!is_device_wlun(to_scsi_device(dev)))
>>>          return -ENODEV;
>>>      blk_pm_runtime_init(dev);
>>>      pm_runtime_set_autosuspend_delay(dev, 0);
>>>      pm_runtime_allow(dev);
>>>
>>> Note sdev_ufs_device will not runtime suspend here unless the
>>> device links have been added and all consumers have suspended.
>>> That is handled separately by the pm_runtime_get_noresume() in
>>> ufshcd_slave_configure() and the pm_runtime_put() when luns_avail == 1
>>> in ufshcd_setup_links().
>>>
>>>> +}
>>>> +
>>>> +static int ufshcd_wl_remove(struct device *dev)
>>>> +{
>>>> +    pm_runtime_forbid(dev);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static const struct dev_pm_ops ufshcd_wl_pm_ops = {
>>>> +#ifdef CONFIG_PM_SLEEP
>>>> +    .suspend = ufshcd_wl_suspend,
>>>> +    .resume = ufshcd_wl_resume,
>>>> +    .freeze = ufshcd_wl_suspend,
>>>> +    .thaw = ufshcd_wl_resume,
>>>> +    .poweroff = ufshcd_wl_poweroff,
>>>> +    .restore = ufshcd_wl_resume,
>>>> +#endif
>>>> +    SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
>>>> +};
>>>> +
>>>> +/**
>>>> + * ufs_dev_wlun_template - describes ufs device wlun
>>>> + * ufs-device wlun - used to send pm commands
>>>> + * All luns are consumers of ufs-device wlun.
>>>> + *
>>>> + * Currently, no sd driver is present for wluns.
>>>> + * Hence the no specific pm operations are performed.
>>>> + * With ufs design, SSU should be sent to ufs-device wlun.
>>>> + * Hence register a scsi driver for ufs wluns only.
>>>> + */
>>>> +static struct scsi_driver ufs_dev_wlun_template = {
>>>> +    .gendrv = {
>>>> +        .name = "ufs_device_wlun",
>>>> +        .owner = THIS_MODULE,
>>>> +        .probe = ufshcd_wl_probe,
>>>> +        .remove = ufshcd_wl_remove,
>>>> +        .pm = &ufshcd_wl_pm_ops,
>>>> +        .shutdown = ufshcd_wl_shutdown,
>>>> +    },
>>>> +};
>>>> +
>>>> +static int ufshcd_rpmb_probe(struct device *dev)
>>>> +{
>>>> +    return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
>>>> +}
>>>> +
>>>> +static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
>>>> +{
>>>> +    int ret = 0;
>>>> +
>>>> +    if (!hba->wlun_rpmb_clr_ua)
>>>> +        return 0;
>>>> +    ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
>>>> +    if (!ret)
>>>> +        hba->wlun_rpmb_clr_ua = 0;
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int ufshcd_rpmb_runtime_resume(struct device *dev)
>>>> +{
>>>> +    struct ufs_hba *hba = wlun_dev_to_hba(dev);
>>>> +
>>>> +    if (hba->sdev_rpmb)
>>>> +        return ufshcd_clear_rpmb_uac(hba);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int ufshcd_rpmb_resume(struct device *dev)
>>>> +{
>>>> +    struct ufs_hba *hba = wlun_dev_to_hba(dev);
>>>> +
>>>> +    if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
>>>> +        return ufshcd_clear_rpmb_uac(hba);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static const struct dev_pm_ops ufs_rpmb_pm_ops = {
>>>> +    SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
>>>> +    SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
>>>> +};
>>>> +
>>>> +/**
>>>> + * Describes the ufs rpmb wlun.
>>>> + * Used only to send uac.
>>>> + */
>>>> +static struct scsi_driver ufs_rpmb_wlun_template = {
>>>> +    .gendrv = {
>>>> +        .name = "ufs_rpmb_wlun",
>>>> +        .owner = THIS_MODULE,
>>>> +        .probe = ufshcd_rpmb_probe,
>>>> +        .pm = &ufs_rpmb_pm_ops,
>>>> +    },
>>>> +};
>>>> +
>>>>    static int __init ufshcd_core_init(void)
>>>>    {
>>>> +    int ret;
>>>> +
>>>>        ufs_debugfs_init();
>>>> +
>>>> +    ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
>>>> +    if (ret) {
>>>> +        ufs_debugfs_exit();
>>>> +        return ret;
>>>> +    }
>>>> +    ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
>>>> +    if (ret) {
>>>> +        ufs_debugfs_exit();
>>>> +        scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>>>> +        return ret;
>>>> +    }
>>>>        return 0;
>>>>    }
>>>>      static void __exit ufshcd_core_exit(void)
>>>>    {
>>>>        ufs_debugfs_exit();
>>>> +    scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);
>>>> +    scsi_unregister_driver(&ufs_rpmb_wlun_template.gendrv);
>>>>    }
>>>>      module_init(ufshcd_core_init);
>>>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>>>> index ee61f82..7841b2a 100644
>>>> --- a/drivers/scsi/ufs/ufshcd.h
>>>> +++ b/drivers/scsi/ufs/ufshcd.h
>>>> @@ -72,6 +72,8 @@ enum ufs_event_type {
>>>>        UFS_EVT_LINK_STARTUP_FAIL,
>>>>        UFS_EVT_RESUME_ERR,
>>>>        UFS_EVT_SUSPEND_ERR,
>>>> +    UFS_EVT_WL_SUSP_ERR,
>>>> +    UFS_EVT_WL_RES_ERR,
>>>>          /* abnormal events */
>>>>        UFS_EVT_DEV_RESET,
>>>> @@ -804,6 +806,7 @@ struct ufs_hba {
>>>>        struct list_head clk_list_head;
>>>>          bool wlun_dev_clr_ua;
>>>> +    bool wlun_rpmb_clr_ua;
>>>>          /* Number of requests aborts */
>>>>        int req_abort_count;
>>>> @@ -841,6 +844,7 @@ struct ufs_hba {
>>>>    #ifdef CONFIG_DEBUG_FS
>>>>        struct dentry *debugfs_root;
>>>>    #endif
>>>> +    u32 luns_avail;
>>>>    };
>>>>      /* Returns true if clocks can be gated. Otherwise false */
>>>> @@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
>>>>                     enum query_opcode desc_op);
>>>>      int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
>>>> +int ufshcd_suspend_prepare(struct device *dev);
>>>> +void ufshcd_resume_complete(struct device *dev);
>>>>      /* Wrapper functions for safely calling variant operations */
>>>>    static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
>>>> diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
>>>> index e151477..d9d233b 100644
>>>> --- a/include/trace/events/ufs.h
>>>> +++ b/include/trace/events/ufs.h
>>>> @@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
>>>>                  int dev_state, int link_state),
>>>>             TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>>    +DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
>>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>>> +              int dev_state, int link_state),
>>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>> +
>>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
>>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>>> +              int dev_state, int link_state),
>>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>> +
>>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
>>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>>> +              int dev_state, int link_state),
>>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>> +
>>>> +DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
>>>> +         TP_PROTO(const char *dev_name, int err, s64 usecs,
>>>> +              int dev_state, int link_state),
>>>> +         TP_ARGS(dev_name, err, usecs, dev_state, link_state));
>>>> +
>>>>    TRACE_EVENT(ufshcd_command,
>>>>        TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
>>>>             unsigned int tag, u32 doorbell, int transfer_len, u32 intr,
>>>>
>>>
>>
>>
> 


-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Adrian Hunter]

On 23/03/21 5:13 pm, Asutosh Das (asd) wrote:
> On 3/22/2021 11:12 PM, Adrian Hunter wrote:
>> On 22/03/21 9:53 pm, Asutosh Das (asd) wrote:
>>> On 3/19/2021 10:47 AM, Adrian Hunter wrote:
>>>> On 19/03/21 2:35 am, Asutosh Das wrote:
>>>>> During runtime-suspend of ufs host, the scsi devices are
>>>>> already suspended and so are the queues associated with them.
>>>>> But the ufs host sends SSU to wlun during its runtime-suspend.
>>>>> During the process blk_queue_enter checks if the queue is not in
>>>>> suspended state. If so, it waits for the queue to resume, and never
>>>>> comes out of it.
>>>>> The commit
>>>>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>>>>> adds the check if the queue is in suspended state in blk_queue_enter().
>>>>>
>>>>> Call trace:
>>>>>    __switch_to+0x174/0x2c4
>>>>>    __schedule+0x478/0x764
>>>>>    schedule+0x9c/0xe0
>>>>>    blk_queue_enter+0x158/0x228
>>>>>    blk_mq_alloc_request+0x40/0xa4
>>>>>    blk_get_request+0x2c/0x70
>>>>>    __scsi_execute+0x60/0x1c4
>>>>>    ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>>>>    ufshcd_suspend+0x208/0x83c
>>>>>    ufshcd_runtime_suspend+0x40/0x154
>>>>>    ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>>>>    pm_generic_runtime_suspend+0x28/0x3c
>>>>>    __rpm_callback+0x80/0x2a4
>>>>>    rpm_suspend+0x308/0x614
>>>>>    rpm_idle+0x158/0x228
>>>>>    pm_runtime_work+0x84/0xac
>>>>>    process_one_work+0x1f0/0x470
>>>>>    worker_thread+0x26c/0x4c8
>>>>>    kthread+0x13c/0x320
>>>>>    ret_from_fork+0x10/0x18
>>>>>
>>>>> Fix this by registering ufs device wlun as a scsi driver and
>>>>> registering it for block runtime-pm. Also make this as a
>>>>> supplier for all other luns. That way, this device wlun
>>>>> suspends after all the consumers and resumes after
>>>>> hba resumes.
>>>>>
>>>>> Co-developed-by: Can Guo <cang@codeaurora.org>
>>>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>>>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>>>>
>>>> I have some more comments that may help straighten things out.
>>>>
>>>> Also please look at ufs_debugfs_get_user_access() and
>>>> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
>>>> sdev_ufs_device.
>>>>
>>>> It would also be good if you could re-base on linux-next.
>>>>
>>>
>>> Hi Adrian
>>> Thanks for the comments.
>>>
>>> I agree moving the code to wlun probe and other changes.
>>> But it looks to me that it may not fully solve the issue.
>>>
>>> Please let me explain my understanding on this:
>>>
>>> (Please refer to the logs in v10)
>>> scsi_autopm_*() are invoked on a sdev.
>>> pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.
>>>
>>> For the device wlun:
>>>      slave_configure():
>>>          - doesn't set the rpm_autosuspend
>>>          - pm_runtime_getnoresume()
>>>      scsi_sysfs_add_sdev():
>>>          - pm_runtime_forbid()
>>>          - scsi_autopm_get_device()
>>>          - device_add()
>>>              - ufshcd_wl_probe()
>>>          - scsi_autopm_put_device()
>>>
>>> For all other scsi devices:
>>>      slave_alloc():
>>>          - ufshcd_setup_links()
>>> Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>
>> With DL_FLAG_RPM_ACTIVE, links will 'get' not 'put'
>>
> I'm referring to the pm_runtime_put(sdev_ufs_device) after all the links are setup, that you suggested to add.

Ok

>>>      slave_configure():
>>>          - set rpm_autosuspend
>>>      scsi_sysfs_add_sdev():
>>>          - scsi_autopm_get_device()
>>>          - device_add() -> schedules an async probe()
>>>          - scsi_autopm_put_device() - (1)
>>>
>>> Now the rpm_put_suppliers() can be invoked *after* pm_runtime_get_suppliers() of the async probe(), since both are running in different contexts.
>>
>> Only if the sd device suspends.
>>
> Correct. What'd stop the sd device from suspending?
> We should be stopping the sd device from suspending here - imho.

You mean for performance reasons.  That is something we can
look at, but let's get it working first.

> 
>>> In that case, the usage_count of supplier would be decremented until rpm_active of this link becomes 1.
>>
>> Right, because the sd device suspended.
>>
>>> Now the pm_runtime_get_suppliers() expects the link_active to be more than 1.
>>
>> Not sure what you mean here. pm_runtime_*put*_suppliers() won't do anything if the link count is 1.
> I'm referring to the logs that I pasted before:
> [    6.941267][    T7] scsi 0:0:0:4: rpm_put_suppliers: [BEF] Supp (0:0:0:49488) usage_count: 4 rpm_active: 3
> 
> ------ T196 Context comes in while T7 is running ----------
> [    6.941466][  T196] scsi 0:0:0:4: pm_runtime_get_suppliers: (0:0:0:49488): supp: usage_count: 5 rpm_active: 4
> --------------------------------------------------------------
> 
> [    7.788397][    T7] scsi 0:0:0:4: rpm_put_suppliers: [AFT] Supp (0:0:0:49488) usage_count: 2 rpm_active: 1
> 
> I meant to say that, if the rpm_put_suppliers() is invoked after the pm_runtime_get_suppliers() as is seen above then the link_active may become 1 even *after* pm_runtime_get_suppliers() is invoked.
> 
> I'm referring to the pm_runtime_get_suppliers() invoked from:
> driver_probe_device() - say for, sd 0:0:0:x
>     |- pm_runtime_get_suppliers() - for sd 0:0:0:49488

I am hoping that was the problem that Rafael's revert dealt with.

>>
>>> Now then, there comes a time, that when sd_probe() schedules a suspend, the supplier usage_count becomes 0 and the link_active becomes 1.
>>> And the supplier suspends before the consumer.
>>
>> sd probe first resumes the sd device which will resume the supplier.
>>
> Correct, but it'd again schedule a suspend (since autosuspend is enabled now) at the end of the sd_probe().
> Thereafter, pm_runtime_put_suppliers()(sd 0:0:0:49488) is invoked from driver_probe_device() which had actually invoked sd_probe().
> That'd make the link_active to 1 even when sd 0:0:0:x is active.

If sd 0:0:0:x is active then rpm_get_suppliers() still has +1 rpm_active. pm_runtime_get_suppliers() also has +1 rpm_active.
i.e. rpm_active is 3. If rpm_put_suppliers() is called, it means sd 0:0:0:x has really runtime suspended (not just waiting for autosuspend.  Otherwise when the probe ends pm_runtime_put_suppliers() will drop rpm_active from 3 to 2.

But it is a bit theoretical.  Let's try it and see.

> 
>>>
>>> So I was wondering, what'd make sure that the pm_runtime_get_suppliers() from driver_probe_device() is invoked after scsi_autopm_put_device() (1) finishes the rpm_put_suppliers().
>>>
>>> Am not sure if I'm missing something in this.
>>> Do you think, the current changes alone can fix the above issue?
>>
>> Yes, but let's see.
>>
> Essentially, we should stop the sd device from runtime suspending until it's probe is done. Then allow the same. Does it make sense?
> Please let me know what you think.

I really think it would be good to try the changes that have been identified and see how it behaves.

Then go from there.

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das (asd)]

On 3/23/2021 12:19 PM, Adrian Hunter wrote:
> On 23/03/21 5:13 pm, Asutosh Das (asd) wrote:
>> On 3/22/2021 11:12 PM, Adrian Hunter wrote:
>>> On 22/03/21 9:53 pm, Asutosh Das (asd) wrote:
>>>> On 3/19/2021 10:47 AM, Adrian Hunter wrote:
>>>>> On 19/03/21 2:35 am, Asutosh Das wrote:
>>>>>> During runtime-suspend of ufs host, the scsi devices are
>>>>>> already suspended and so are the queues associated with them.
>>>>>> But the ufs host sends SSU to wlun during its runtime-suspend.
>>>>>> During the process blk_queue_enter checks if the queue is not in
>>>>>> suspended state. If so, it waits for the queue to resume, and never
>>>>>> comes out of it.
>>>>>> The commit
>>>>>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>>>>>> adds the check if the queue is in suspended state in blk_queue_enter().
>>>>>>
>>>>>> Call trace:
>>>>>>     __switch_to+0x174/0x2c4
>>>>>>     __schedule+0x478/0x764
>>>>>>     schedule+0x9c/0xe0
>>>>>>     blk_queue_enter+0x158/0x228
>>>>>>     blk_mq_alloc_request+0x40/0xa4
>>>>>>     blk_get_request+0x2c/0x70
>>>>>>     __scsi_execute+0x60/0x1c4
>>>>>>     ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>>>>>     ufshcd_suspend+0x208/0x83c
>>>>>>     ufshcd_runtime_suspend+0x40/0x154
>>>>>>     ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>>>>>     pm_generic_runtime_suspend+0x28/0x3c
>>>>>>     __rpm_callback+0x80/0x2a4
>>>>>>     rpm_suspend+0x308/0x614
>>>>>>     rpm_idle+0x158/0x228
>>>>>>     pm_runtime_work+0x84/0xac
>>>>>>     process_one_work+0x1f0/0x470
>>>>>>     worker_thread+0x26c/0x4c8
>>>>>>     kthread+0x13c/0x320
>>>>>>     ret_from_fork+0x10/0x18
>>>>>>
>>>>>> Fix this by registering ufs device wlun as a scsi driver and
>>>>>> registering it for block runtime-pm. Also make this as a
>>>>>> supplier for all other luns. That way, this device wlun
>>>>>> suspends after all the consumers and resumes after
>>>>>> hba resumes.
>>>>>>
>>>>>> Co-developed-by: Can Guo <cang@codeaurora.org>
>>>>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>>>>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>>>>>
>>>>> I have some more comments that may help straighten things out.
>>>>>
>>>>> Also please look at ufs_debugfs_get_user_access() and
>>>>> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
>>>>> sdev_ufs_device.
>>>>>
>>>>> It would also be good if you could re-base on linux-next.
>>>>>
>>>>
>>>> Hi Adrian
>>>> Thanks for the comments.
>>>>
>>>> I agree moving the code to wlun probe and other changes.
>>>> But it looks to me that it may not fully solve the issue.
>>>>
>>>> Please let me explain my understanding on this:
>>>>
>>>> (Please refer to the logs in v10)
>>>> scsi_autopm_*() are invoked on a sdev.
>>>> pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.
>>>>
>>>> For the device wlun:
>>>>       slave_configure():
>>>>           - doesn't set the rpm_autosuspend
>>>>           - pm_runtime_getnoresume()
>>>>       scsi_sysfs_add_sdev():
>>>>           - pm_runtime_forbid()
>>>>           - scsi_autopm_get_device()
>>>>           - device_add()
>>>>               - ufshcd_wl_probe()
>>>>           - scsi_autopm_put_device()
>>>>
>>>> For all other scsi devices:
>>>>       slave_alloc():
>>>>           - ufshcd_setup_links()
>>>> Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>>
>>> With DL_FLAG_RPM_ACTIVE, links will 'get' not 'put'
>>>
>> I'm referring to the pm_runtime_put(sdev_ufs_device) after all the links are setup, that you suggested to add.
> 
> Ok
> 
>>>>       slave_configure():
>>>>           - set rpm_autosuspend
>>>>       scsi_sysfs_add_sdev():
>>>>           - scsi_autopm_get_device()
>>>>           - device_add() -> schedules an async probe()
>>>>           - scsi_autopm_put_device() - (1)
>>>>
>>>> Now the rpm_put_suppliers() can be invoked *after* pm_runtime_get_suppliers() of the async probe(), since both are running in different contexts.
>>>
>>> Only if the sd device suspends.
>>>
>> Correct. What'd stop the sd device from suspending?
>> We should be stopping the sd device from suspending here - imho.
> 

Hi Adrian,
Thanks for the comments.

> You mean for performance reasons.  That is something we can
> look at, but let's get it working first.
> 
Not for performance reasons. I meant to say that this issue can be fixed 
if we stop the sd devices from suspending until the sd_probe() is completed.
>>
>>>> In that case, the usage_count of supplier would be decremented until rpm_active of this link becomes 1.
>>>
>>> Right, because the sd device suspended.
>>>
>>>> Now the pm_runtime_get_suppliers() expects the link_active to be more than 1.
>>>
>>> Not sure what you mean here. pm_runtime_*put*_suppliers() won't do anything if the link count is 1.
>> I'm referring to the logs that I pasted before:
>> [    6.941267][    T7] scsi 0:0:0:4: rpm_put_suppliers: [BEF] Supp (0:0:0:49488) usage_count: 4 rpm_active: 3
>>
>> ------ T196 Context comes in while T7 is running ----------
>> [    6.941466][  T196] scsi 0:0:0:4: pm_runtime_get_suppliers: (0:0:0:49488): supp: usage_count: 5 rpm_active: 4
>> --------------------------------------------------------------
>>
>> [    7.788397][    T7] scsi 0:0:0:4: rpm_put_suppliers: [AFT] Supp (0:0:0:49488) usage_count: 2 rpm_active: 1
>>
>> I meant to say that, if the rpm_put_suppliers() is invoked after the pm_runtime_get_suppliers() as is seen above then the link_active may become 1 even *after* pm_runtime_get_suppliers() is invoked.
>>
>> I'm referring to the pm_runtime_get_suppliers() invoked from:
>> driver_probe_device() - say for, sd 0:0:0:x
>>      |- pm_runtime_get_suppliers() - for sd 0:0:0:49488
> 
> I am hoping that was the problem that Rafael's revert dealt with.
> 
I think the issue is in the sequence of events.
If rpm_put_suppliers() runs after pm_runtime_get_suppliers() this issue 
can occur.

>>>
>>>> Now then, there comes a time, that when sd_probe() schedules a suspend, the supplier usage_count becomes 0 and the link_active becomes 1.
>>>> And the supplier suspends before the consumer.
>>>
>>> sd probe first resumes the sd device which will resume the supplier.
>>>
>> Correct, but it'd again schedule a suspend (since autosuspend is enabled now) at the end of the sd_probe().
>> Thereafter, pm_runtime_put_suppliers()(sd 0:0:0:49488) is invoked from driver_probe_device() which had actually invoked sd_probe().
>> That'd make the link_active to 1 even when sd 0:0:0:x is active.
> 
> If sd 0:0:0:x is active then rpm_get_suppliers() still has +1 rpm_active. pm_runtime_get_suppliers() also has +1 rpm_active.
> i.e. rpm_active is 3. If rpm_put_suppliers() is called, it means sd 0:0:0:x has really runtime suspended (not just waiting for autosuspend.  Otherwise when the probe ends pm_runtime_put_suppliers() will drop rpm_active from 3 to 2.
In the good case it'd drop from 3 to 2. But in the bad case, I see that 
it drops to 1. That's when the supplier suspends before the consumer.
That would happen when rpm_put_suppliers() runs after the 
pm_runtime_get_suppliers() is completed and decrements the usage_count 
of supplier until link_active is 1. At that point yes, sd 0:0:0:x has 
really runtime-suspended. sd_probe() would resume it and schedule a 
suspend at the end of probe.

IIUC, below is the sequence of events that can lead to this issue:
1. sd 0:0:0:x schedules an async probe
2. sd 0:0:0:x invokes scsi_autopm_put_device()
3. async probe completes pm_runtime_get_suppliers() increments the 
rpm_active.
4. suspend of sd 0:0:0:x is invoked and rpm_put_suppliers() is invoked 
which decrements the link_active (this was incremented in 3 above)
5. sd_probe() is invoked which resumes it and schedules a suspend
6. pm_runtime_put_suppliers() is invoked which decreases the link_active 
to 1 and supplier suspends before the consumer.

So my solution was to stop sd 0:0:0:x from runtime suspending until the 
sd_probe() is done.

> 
> But it is a bit theoretical.  Let's try it and see.
> 
>>
>>>>
>>>> So I was wondering, what'd make sure that the pm_runtime_get_suppliers() from driver_probe_device() is invoked after scsi_autopm_put_device() (1) finishes the rpm_put_suppliers().
>>>>
>>>> Am not sure if I'm missing something in this.
>>>> Do you think, the current changes alone can fix the above issue?
>>>
>>> Yes, but let's see.
>>>
>> Essentially, we should stop the sd device from runtime suspending until it's probe is done. Then allow the same. Does it make sense?
>> Please let me know what you think.
> 
> I really think it would be good to try the changes that have been identified and see how it behaves.
> 
> Then go from there.
> 
Sure, I've pushed the changes v13 today.
I will test it after the changes are finalized.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun

[Adrian Hunter]

On 25/03/21 4:14 am, Asutosh Das (asd) wrote:
> On 3/23/2021 12:19 PM, Adrian Hunter wrote:
>> On 23/03/21 5:13 pm, Asutosh Das (asd) wrote:
>>> On 3/22/2021 11:12 PM, Adrian Hunter wrote:
>>>> On 22/03/21 9:53 pm, Asutosh Das (asd) wrote:
>>>>> On 3/19/2021 10:47 AM, Adrian Hunter wrote:
>>>>>> On 19/03/21 2:35 am, Asutosh Das wrote:
>>>>>>> During runtime-suspend of ufs host, the scsi devices are
>>>>>>> already suspended and so are the queues associated with them.
>>>>>>> But the ufs host sends SSU to wlun during its runtime-suspend.
>>>>>>> During the process blk_queue_enter checks if the queue is not in
>>>>>>> suspended state. If so, it waits for the queue to resume, and never
>>>>>>> comes out of it.
>>>>>>> The commit
>>>>>>> (d55d15a33: scsi: block: Do not accept any requests while suspended)
>>>>>>> adds the check if the queue is in suspended state in blk_queue_enter().
>>>>>>>
>>>>>>> Call trace:
>>>>>>>     __switch_to+0x174/0x2c4
>>>>>>>     __schedule+0x478/0x764
>>>>>>>     schedule+0x9c/0xe0
>>>>>>>     blk_queue_enter+0x158/0x228
>>>>>>>     blk_mq_alloc_request+0x40/0xa4
>>>>>>>     blk_get_request+0x2c/0x70
>>>>>>>     __scsi_execute+0x60/0x1c4
>>>>>>>     ufshcd_set_dev_pwr_mode+0x124/0x1e4
>>>>>>>     ufshcd_suspend+0x208/0x83c
>>>>>>>     ufshcd_runtime_suspend+0x40/0x154
>>>>>>>     ufshcd_pltfrm_runtime_suspend+0x14/0x20
>>>>>>>     pm_generic_runtime_suspend+0x28/0x3c
>>>>>>>     __rpm_callback+0x80/0x2a4
>>>>>>>     rpm_suspend+0x308/0x614
>>>>>>>     rpm_idle+0x158/0x228
>>>>>>>     pm_runtime_work+0x84/0xac
>>>>>>>     process_one_work+0x1f0/0x470
>>>>>>>     worker_thread+0x26c/0x4c8
>>>>>>>     kthread+0x13c/0x320
>>>>>>>     ret_from_fork+0x10/0x18
>>>>>>>
>>>>>>> Fix this by registering ufs device wlun as a scsi driver and
>>>>>>> registering it for block runtime-pm. Also make this as a
>>>>>>> supplier for all other luns. That way, this device wlun
>>>>>>> suspends after all the consumers and resumes after
>>>>>>> hba resumes.
>>>>>>>
>>>>>>> Co-developed-by: Can Guo <cang@codeaurora.org>
>>>>>>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>>>>>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
>>>>>>
>>>>>> I have some more comments that may help straighten things out.
>>>>>>
>>>>>> Also please look at ufs_debugfs_get_user_access() and
>>>>>> ufs_debugfs_put_user_access() that now need to scsi_autopm_get/put_device
>>>>>> sdev_ufs_device.
>>>>>>
>>>>>> It would also be good if you could re-base on linux-next.
>>>>>>
>>>>>
>>>>> Hi Adrian
>>>>> Thanks for the comments.
>>>>>
>>>>> I agree moving the code to wlun probe and other changes.
>>>>> But it looks to me that it may not fully solve the issue.
>>>>>
>>>>> Please let me explain my understanding on this:
>>>>>
>>>>> (Please refer to the logs in v10)
>>>>> scsi_autopm_*() are invoked on a sdev.
>>>>> pm_runtime_get_suppliers()/rpm_put_suppliers() are on the supplier device.
>>>>>
>>>>> For the device wlun:
>>>>>       slave_configure():
>>>>>           - doesn't set the rpm_autosuspend
>>>>>           - pm_runtime_getnoresume()
>>>>>       scsi_sysfs_add_sdev():
>>>>>           - pm_runtime_forbid()
>>>>>           - scsi_autopm_get_device()
>>>>>           - device_add()
>>>>>               - ufshcd_wl_probe()
>>>>>           - scsi_autopm_put_device()
>>>>>
>>>>> For all other scsi devices:
>>>>>       slave_alloc():
>>>>>           - ufshcd_setup_links()
>>>>> Say all link_add: pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
>>>>
>>>> With DL_FLAG_RPM_ACTIVE, links will 'get' not 'put'
>>>>
>>> I'm referring to the pm_runtime_put(sdev_ufs_device) after all the links are setup, that you suggested to add.
>>
>> Ok
>>
>>>>>       slave_configure():
>>>>>           - set rpm_autosuspend
>>>>>       scsi_sysfs_add_sdev():
>>>>>           - scsi_autopm_get_device()
>>>>>           - device_add() -> schedules an async probe()
>>>>>           - scsi_autopm_put_device() - (1)
>>>>>
>>>>> Now the rpm_put_suppliers() can be invoked *after* pm_runtime_get_suppliers() of the async probe(), since both are running in different contexts.
>>>>
>>>> Only if the sd device suspends.
>>>>
>>> Correct. What'd stop the sd device from suspending?
>>> We should be stopping the sd device from suspending here - imho.
>>
> 
> Hi Adrian,
> Thanks for the comments.
> 
>> You mean for performance reasons.  That is something we can
>> look at, but let's get it working first.
>>
> Not for performance reasons. I meant to say that this issue can be fixed if we stop the sd devices from suspending until the sd_probe() is completed.

To me that looks like hiding the problem rather than fixing it.

For example, Rafael's revert was a real issue that we uncovered.

From a maintenance point of view, hiding problems rather than
fixing them, creates an unsustainable technical debt for the
future.

>>>
>>>>> In that case, the usage_count of supplier would be decremented until rpm_active of this link becomes 1.
>>>>
>>>> Right, because the sd device suspended.
>>>>
>>>>> Now the pm_runtime_get_suppliers() expects the link_active to be more than 1.
>>>>
>>>> Not sure what you mean here. pm_runtime_*put*_suppliers() won't do anything if the link count is 1.
>>> I'm referring to the logs that I pasted before:
>>> [    6.941267][    T7] scsi 0:0:0:4: rpm_put_suppliers: [BEF] Supp (0:0:0:49488) usage_count: 4 rpm_active: 3
>>>
>>> ------ T196 Context comes in while T7 is running ----------
>>> [    6.941466][  T196] scsi 0:0:0:4: pm_runtime_get_suppliers: (0:0:0:49488): supp: usage_count: 5 rpm_active: 4
>>> --------------------------------------------------------------
>>>
>>> [    7.788397][    T7] scsi 0:0:0:4: rpm_put_suppliers: [AFT] Supp (0:0:0:49488) usage_count: 2 rpm_active: 1
>>>
>>> I meant to say that, if the rpm_put_suppliers() is invoked after the pm_runtime_get_suppliers() as is seen above then the link_active may become 1 even *after* pm_runtime_get_suppliers() is invoked.
>>>
>>> I'm referring to the pm_runtime_get_suppliers() invoked from:
>>> driver_probe_device() - say for, sd 0:0:0:x
>>>      |- pm_runtime_get_suppliers() - for sd 0:0:0:49488
>>
>> I am hoping that was the problem that Rafael's revert dealt with.
>>
> I think the issue is in the sequence of events.
> If rpm_put_suppliers() runs after pm_runtime_get_suppliers() this issue can occur.

Then it would be a core PM issue not a UFS issue.

> 
>>>>
>>>>> Now then, there comes a time, that when sd_probe() schedules a suspend, the supplier usage_count becomes 0 and the link_active becomes 1.
>>>>> And the supplier suspends before the consumer.
>>>>
>>>> sd probe first resumes the sd device which will resume the supplier.
>>>>
>>> Correct, but it'd again schedule a suspend (since autosuspend is enabled now) at the end of the sd_probe().
>>> Thereafter, pm_runtime_put_suppliers()(sd 0:0:0:49488) is invoked from driver_probe_device() which had actually invoked sd_probe().
>>> That'd make the link_active to 1 even when sd 0:0:0:x is active.
>>
>> If sd 0:0:0:x is active then rpm_get_suppliers() still has +1 rpm_active. pm_runtime_get_suppliers() also has +1 rpm_active.
>> i.e. rpm_active is 3. If rpm_put_suppliers() is called, it means sd 0:0:0:x has really runtime suspended (not just waiting for autosuspend.  Otherwise when the probe ends pm_runtime_put_suppliers() will drop rpm_active from 3 to 2.
> In the good case it'd drop from 3 to 2. But in the bad case, I see that it drops to 1. That's when the supplier suspends before the consumer.
> That would happen when rpm_put_suppliers() runs after the pm_runtime_get_suppliers() is completed and decrements the usage_count of supplier until link_active is 1. At that point yes, sd 0:0:0:x has really runtime-suspended. sd_probe() would resume it and schedule a suspend at the end of probe.
> 
> IIUC, below is the sequence of events that can lead to this issue:
> 1. sd 0:0:0:x schedules an async probe
> 2. sd 0:0:0:x invokes scsi_autopm_put_device()
> 3. async probe completes pm_runtime_get_suppliers() increments the rpm_active.
> 4. suspend of sd 0:0:0:x is invoked and rpm_put_suppliers() is invoked which decrements the link_active (this was incremented in 3 above)
> 5. sd_probe() is invoked which resumes it and schedules a suspend
> 6. pm_runtime_put_suppliers() is invoked which decreases the link_active to 1 and supplier suspends before the consumer.
> 
> So my solution was to stop sd 0:0:0:x from runtime suspending until the sd_probe() is done.

I'll look into it, but maybe the following would help:

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 18b82427d0cb..4f708b2a9359 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -312,6 +312,7 @@ static void rpm_put_suppliers(struct device *dev)
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
 				device_links_read_lock_held()) {
 
+		link->supplier_preactivated = false;
 		while (refcount_dec_not_one(&link->rpm_active))
 			pm_runtime_put(link->supplier);
 	}



> 
>>
>> But it is a bit theoretical.  Let's try it and see.
>>
>>>
>>>>>
>>>>> So I was wondering, what'd make sure that the pm_runtime_get_suppliers() from driver_probe_device() is invoked after scsi_autopm_put_device() (1) finishes the rpm_put_suppliers().
>>>>>
>>>>> Am not sure if I'm missing something in this.
>>>>> Do you think, the current changes alone can fix the above issue?
>>>>
>>>> Yes, but let's see.
>>>>
>>> Essentially, we should stop the sd device from runtime suspending until it's probe is done. Then allow the same. Does it make sense?
>>> Please let me know what you think.
>>
>> I really think it would be good to try the changes that have been identified and see how it behaves.
>>
>> Then go from there.
>>
> Sure, I've pushed the changes v13 today.
> I will test it after the changes are finalized.
> 

Thank you! :-)