[PATCH 00/13] hisi_sas: Some misc patches

[PATCH 00/13] hisi_sas: Some misc patches

[John Garry]

This patchset includes support for some more minor features, a bit of
tidying, and a few patches to make the driver a bit more robust.

Notables:
- BIST phy loopback support
- Fix for NCQ tags
- Correctly config registers after controller reset

Luo Jiaxing (7):
  scsi: hisi_sas: add debugfs auto-trigger for internal abort time out
  scsi: hisi_sas: Use true/false as input parameter of sas_phy_reset()
  scsi: hisi_sas: Directly return when running I_T_nexus reset if phy
    disabled
  scsi: hisi_sas: Remove sleep after issue phy reset if
    sas_smp_phy_control() fails
  scsi: hisi_sas: Remove hisi_sas_hw.slot_complete
  scsi: hisi_sas: Remove some unused function arguments
  scsi: hisi_sas: Add hisi_sas_debugfs_alloc() to centralise allocation

Xiang Chen (6):
  scsi: hisi_sas: Retry 3 times TMF IO for SAS disks when init device
  scsi: hisi_sas: Update all the registers after suspend and resume
  scsi: hisi_sas: Assign NCQ tag for all NCQ commands
  scsi: hisi_sas: Remove redundant work declaration
  scsi: hisi_sas: Add BIST support for phy loopback
  scsi: hisi_sas: Fix the conflict between device gone and host reset

 drivers/scsi/hisi_sas/hisi_sas.h       |  18 +-
 drivers/scsi/hisi_sas/hisi_sas_main.c  | 569 +++++++++++++++++++++----
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c |   1 -
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |  17 +-
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 159 ++++++-
 5 files changed, 661 insertions(+), 103 deletions(-)

-- 
2.17.1

[PATCH 01/13] scsi: hisi_sas: add debugfs auto-trigger for internal abort time out

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

This trigger is add at _hisi_sas_internal_task_abort()

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index d60eaaa4c5e8..03e953862412 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -2060,6 +2060,9 @@ _hisi_sas_internal_task_abort(struct hisi_hba *hisi_hba,
 
 	/* Internal abort timed out */
 	if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
+		if (hisi_sas_debugfs_enable && hisi_hba->debugfs_itct)
+			queue_work(hisi_hba->wq, &hisi_hba->debugfs_work);
+
 		if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
 			struct hisi_sas_slot *slot = task->lldd_task;
 
-- 
2.17.1

[PATCH 02/13] scsi: hisi_sas: Use true/false as input parameter of sas_phy_reset()

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

When calling sas_phy_reset(), we need to specify whether the reset type
is hard reset or link reset - use true/false for clarity.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 03e953862412..47faa283312e 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1762,7 +1762,7 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 	}
 
 	reset_type = (sas_dev->dev_status == HISI_SAS_DEV_INIT ||
-		      !dev_is_sata(device)) ? 1 : 0;
+		      !dev_is_sata(device)) ? true : false;
 
 	rc = sas_phy_reset(local_phy, reset_type);
 	sas_put_local_phy(local_phy);
@@ -1843,7 +1843,7 @@ static int hisi_sas_lu_reset(struct domain_device *device, u8 *lun)
 
 		phy = sas_get_local_phy(device);
 
-		rc = sas_phy_reset(phy, 1);
+		rc = sas_phy_reset(phy, true);
 
 		if (rc == 0)
 			hisi_sas_release_task(hisi_hba, device);
-- 
2.17.1

[PATCH 03/13] scsi: hisi_sas: Directly return when running I_T_nexus reset if phy disabled

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

At hisi_sas_debug_I_T_nexus_reset(), we call sas_phy_reset() to reset a
phy. But if the phy is disabled, sas_phy_reset() will directly return
-ENODEV without issue a phy reset request.

If so, We can directly return -ENODEV to libsas before issue a phy
reset.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 47faa283312e..5642c53cccae 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1752,6 +1752,11 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 	DECLARE_COMPLETION_ONSTACK(phyreset);
 	int rc, reset_type;
 
+	if (!local_phy->enabled) {
+		sas_put_local_phy(local_phy);
+		return -ENODEV;
+	}
+
 	if (scsi_is_sas_phy_local(local_phy)) {
 		struct asd_sas_phy *sas_phy =
 			sas_ha->sas_phy[local_phy->number];
-- 
2.17.1

[PATCH 04/13] scsi: hisi_sas: Remove sleep after issue phy reset if sas_smp_phy_control() fails

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

At expander environment, we delay after issue phy reset to wait for
hardware to handle phy reset. But if sas_smp_phy_control() fails, the
delay is unnecessary so remove it.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 5642c53cccae..247268983df9 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1791,9 +1791,10 @@ static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 	} else if (sas_dev->dev_status != HISI_SAS_DEV_INIT) {
 		/*
 		 * If in init state, we rely on caller to wait for link to be
-		 * ready; otherwise, delay.
+		 * ready; otherwise, except phy reset is fail, delay.
 		 */
-		msleep(2000);
+		if (!rc)
+			msleep(2000);
 	}
 
 	return rc;
-- 
2.17.1

[PATCH 05/13] scsi: hisi_sas: Retry 3 times TMF IO for SAS disks when init device

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

When init device for SAS disks, it will send TMF IO to clear disks. At that
times TMF IO is broken by some operations such as injecting controller
reset from HW RAs event, the TMF IO will be timeout, and at last device
will be gone. Print is as followed:

hisi_sas_v3_hw 0000:74:02.0: dev[240:1] found
...
hisi_sas_v3_hw 0000:74:02.0: controller resetting...
hisi_sas_v3_hw 0000:74:02.0: phyup: phy7 link_rate=10(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy0 link_rate=9(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy1 link_rate=9(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy2 link_rate=9(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy3 link_rate=9(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy6 link_rate=10(sata)
hisi_sas_v3_hw 0000:74:02.0: phyup: phy5 link_rate=11
hisi_sas_v3_hw 0000:74:02.0: phyup: phy4 link_rate=11
hisi_sas_v3_hw 0000:74:02.0: controller reset complete
hisi_sas_v3_hw 0000:74:02.0: abort tmf: TMF task timeout and not done
hisi_sas_v3_hw 0000:74:02.0: dev[240:1] is gone
sas: driver on host 0000:74:02.0 cannot handle device 5000c500a75a860d,
error:5

To improve the reliability, retry TMF IO max of 3 times for SAS disks which
is the same as softreset does.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 247268983df9..4c279a285c20 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -698,13 +698,13 @@ static struct hisi_sas_device *hisi_sas_alloc_dev(struct domain_device *device)
 	return sas_dev;
 }
 
-#define HISI_SAS_SRST_ATA_DISK_CNT 3
+#define HISI_SAS_DISK_RECOVER_CNT 3
 static int hisi_sas_init_device(struct domain_device *device)
 {
 	int rc = TMF_RESP_FUNC_COMPLETE;
 	struct scsi_lun lun;
 	struct hisi_sas_tmf_task tmf_task;
-	int retry = HISI_SAS_SRST_ATA_DISK_CNT;
+	int retry = HISI_SAS_DISK_RECOVER_CNT;
 	struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
 	struct device *dev = hisi_hba->dev;
 	struct sas_phy *local_phy;
@@ -714,10 +714,14 @@ static int hisi_sas_init_device(struct domain_device *device)
 		int_to_scsilun(0, &lun);
 
 		tmf_task.tmf = TMF_CLEAR_TASK_SET;
-		rc = hisi_sas_debug_issue_ssp_tmf(device, lun.scsi_lun,
-						  &tmf_task);
-		if (rc == TMF_RESP_FUNC_COMPLETE)
-			hisi_sas_release_task(hisi_hba, device);
+		while (retry-- > 0) {
+			rc = hisi_sas_debug_issue_ssp_tmf(device, lun.scsi_lun,
+							  &tmf_task);
+			if (rc == TMF_RESP_FUNC_COMPLETE) {
+				hisi_sas_release_task(hisi_hba, device);
+				break;
+			}
+		}
 		break;
 	case SAS_SATA_DEV:
 	case SAS_SATA_PM:
-- 
2.17.1

[PATCH 06/13] scsi: hisi_sas: Update all the registers after suspend and resume

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

After suspend and resume, the HW registers will be set back to their
initial value. We use init_reg_v3_hw() to set some registers, but some
registers are set via firmware in ACPI "_RST" method, so add reset
handler before init_reg_v3_hw().

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 2adb5c93bd81..4c32088b9199 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -3283,15 +3283,21 @@ static int hisi_sas_v3_resume(struct pci_dev *pdev)
 	pci_enable_wake(pdev, PCI_D0, 0);
 	pci_restore_state(pdev);
 	rc = pci_enable_device(pdev);
-	if (rc)
+	if (rc) {
 		dev_err(dev, "enable device failed during resume (%d)\n", rc);
+		return rc;
+	}
 
 	pci_set_master(pdev);
 	scsi_unblock_requests(shost);
 	clear_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
 
 	sas_prep_resume_ha(sha);
-	init_reg_v3_hw(hisi_hba);
+	rc = hw_init_v3_hw(hisi_hba);
+	if (rc) {
+		scsi_remove_host(shost);
+		pci_disable_device(pdev);
+	}
 	hisi_hba->hw->phys_init(hisi_hba);
 	sas_resume_ha(sha);
 	clear_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags);
-- 
2.17.1

[PATCH 07/13] scsi: hisi_sas: Assign NCQ tag for all NCQ commands

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

Currently the NCQ tag is only assigned for FPDMA READ and FPDMA WRITE
commands, and for other NCQ commands (such as FPDMA SEND), their NCQ
tags are set in the delivery command to 0.

So for all the NCQ commands, we also need to assign normal NCQ tag for
them, so drop the command type check in hisi_sas_get_ncq_tag() [drop
hisi_sas_get_ncq_tag() altogether actually], and always use the ATA
command NCQ tag when appropriate.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |  1 -
 drivers/scsi/hisi_sas/hisi_sas_main.c  | 15 ---------------
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |  5 ++++-
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c |  5 ++++-
 4 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index fd998d07ffcd..a72d06d973ff 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -559,7 +559,6 @@ extern u8 hisi_sas_get_ata_protocol(struct host_to_dev_fis *fis,
 extern struct hisi_sas_port *to_hisi_sas_port(struct asd_sas_port *sas_port);
 extern void hisi_sas_sata_done(struct sas_task *task,
 			    struct hisi_sas_slot *slot);
-extern int hisi_sas_get_ncq_tag(struct sas_task *task, u32 *tag);
 extern int hisi_sas_get_fw_info(struct hisi_hba *hisi_hba);
 extern int hisi_sas_probe(struct platform_device *pdev,
 			  const struct hisi_sas_hw *ops);
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 4c279a285c20..efd0ddf24e99 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -118,21 +118,6 @@ void hisi_sas_sata_done(struct sas_task *task,
 }
 EXPORT_SYMBOL_GPL(hisi_sas_sata_done);
 
-int hisi_sas_get_ncq_tag(struct sas_task *task, u32 *tag)
-{
-	struct ata_queued_cmd *qc = task->uldd_task;
-
-	if (qc) {
-		if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
-			qc->tf.command == ATA_CMD_FPDMA_READ) {
-			*tag = qc->tag;
-			return 1;
-		}
-	}
-	return 0;
-}
-EXPORT_SYMBOL_GPL(hisi_sas_get_ncq_tag);
-
 /*
  * This function assumes linkrate mask fits in 8 bits, which it
  * does for all HW versions supported.
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index fba4fcad4735..9d316f28c74c 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -2534,7 +2534,10 @@ static void prep_ata_v2_hw(struct hisi_hba *hisi_hba,
 	hdr->dw1 = cpu_to_le32(dw1);
 
 	/* dw2 */
-	if (task->ata_task.use_ncq && hisi_sas_get_ncq_tag(task, &hdr_tag)) {
+	if (task->ata_task.use_ncq) {
+		struct ata_queued_cmd *qc = task->uldd_task;
+
+		hdr_tag = qc->tag;
 		task->ata_task.fis.sector_count |= (u8) (hdr_tag << 3);
 		dw2 |= hdr_tag << CMD_HDR_NCQ_TAG_OFF;
 	}
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 4c32088b9199..cd901213a59b 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1356,7 +1356,10 @@ static void prep_ata_v3_hw(struct hisi_hba *hisi_hba,
 	hdr->dw1 = cpu_to_le32(dw1);
 
 	/* dw2 */
-	if (task->ata_task.use_ncq && hisi_sas_get_ncq_tag(task, &hdr_tag)) {
+	if (task->ata_task.use_ncq) {
+		struct ata_queued_cmd *qc = task->uldd_task;
+
+		hdr_tag = qc->tag;
 		task->ata_task.fis.sector_count |= (u8) (hdr_tag << 3);
 		dw2 |= hdr_tag << CMD_HDR_NCQ_TAG_OFF;
 	}
-- 
2.17.1

[PATCH 08/13] scsi: hisi_sas: Remove hisi_sas_hw.slot_complete

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

We never call hisi_sas_hw.slot_complete, so remove it.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       | 2 --
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 1 -
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 1 -
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 1 -
 4 files changed, 5 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index a72d06d973ff..a6b53d29a8a1 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -289,8 +289,6 @@ struct hisi_sas_hw {
 	void (*prep_abort)(struct hisi_hba *hisi_hba,
 			  struct hisi_sas_slot *slot,
 			  int device_id, int abort_flag, int tag_to_abort);
-	int (*slot_complete)(struct hisi_hba *hisi_hba,
-			     struct hisi_sas_slot *slot);
 	void (*phys_init)(struct hisi_hba *hisi_hba);
 	void (*phy_start)(struct hisi_hba *hisi_hba, int phy_no);
 	void (*phy_disable)(struct hisi_hba *hisi_hba, int phy_no);
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
index 3a584feca843..b861a0f14c9d 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
@@ -1782,7 +1782,6 @@ static const struct hisi_sas_hw hisi_sas_v1_hw = {
 	.prep_smp = prep_smp_v1_hw,
 	.prep_ssp = prep_ssp_v1_hw,
 	.start_delivery = start_delivery_v1_hw,
-	.slot_complete = slot_complete_v1_hw,
 	.phys_init = phys_init_v1_hw,
 	.phy_start = start_phy_v1_hw,
 	.phy_disable = disable_phy_v1_hw,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index 9d316f28c74c..b01ccb38b00a 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3561,7 +3561,6 @@ static const struct hisi_sas_hw hisi_sas_v2_hw = {
 	.prep_stp = prep_ata_v2_hw,
 	.prep_abort = prep_abort_v2_hw,
 	.start_delivery = start_delivery_v2_hw,
-	.slot_complete = slot_complete_v2_hw,
 	.phys_init = phys_init_v2_hw,
 	.phy_start = start_phy_v2_hw,
 	.phy_disable = disable_phy_v2_hw,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index cd901213a59b..0a159df87d7b 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2961,7 +2961,6 @@ static const struct hisi_sas_hw hisi_sas_v3_hw = {
 	.prep_stp = prep_ata_v3_hw,
 	.prep_abort = prep_abort_v3_hw,
 	.start_delivery = start_delivery_v3_hw,
-	.slot_complete = slot_complete_v3_hw,
 	.phys_init = phys_init_v3_hw,
 	.phy_start = start_phy_v3_hw,
 	.phy_disable = disable_phy_v3_hw,
-- 
2.17.1

[PATCH 09/13] scsi: hisi_sas: Remove redundant work declaration

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

Remove redundant work declaration in HISI_SAS_DECLARE_RST_WORK_ON_STACK

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index a6b53d29a8a1..d02ab2699b9b 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -134,7 +134,6 @@ struct hisi_sas_rst {
 
 #define HISI_SAS_DECLARE_RST_WORK_ON_STACK(r) \
 	DECLARE_COMPLETION_ONSTACK(c); \
-	DECLARE_WORK(w, hisi_sas_sync_rst_work_handler); \
 	struct hisi_sas_rst r = HISI_SAS_RST_WORK_INIT(r, c)
 
 enum hisi_sas_bit_err_type {
-- 
2.17.1

[PATCH 10/13] scsi: hisi_sas: Remove some unused function arguments

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

Some function arguments are unused, so remove them.

Also move the timeout print in for wait_cmds_complete_timeout_vX_hw()
callsites into that same function.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |  4 ++--
 drivers/scsi/hisi_sas/hisi_sas_main.c  |  5 ++---
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 11 ++++++-----
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 17 +++++++----------
 4 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index d02ab2699b9b..ccbe4563402a 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -306,8 +306,8 @@ struct hisi_sas_hw {
 	u32 (*get_phys_state)(struct hisi_hba *hisi_hba);
 	int (*write_gpio)(struct hisi_hba *hisi_hba, u8 reg_type,
 				u8 reg_index, u8 reg_count, u8 *write_data);
-	int (*wait_cmds_complete_timeout)(struct hisi_hba *hisi_hba,
-					  int delay_ms, int timeout_ms);
+	void (*wait_cmds_complete_timeout)(struct hisi_hba *hisi_hba,
+					   int delay_ms, int timeout_ms);
 	void (*snapshot_prepare)(struct hisi_hba *hisi_hba);
 	void (*snapshot_restore)(struct hisi_hba *hisi_hba);
 	void (*read_iost_itct_cache)(struct hisi_hba *hisi_hba,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index efd0ddf24e99..b96732493137 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1391,8 +1391,7 @@ static void hisi_sas_refresh_port_id(struct hisi_hba *hisi_hba)
 	}
 }
 
-static void hisi_sas_rescan_topology(struct hisi_hba *hisi_hba, u32 old_state,
-			      u32 state)
+static void hisi_sas_rescan_topology(struct hisi_hba *hisi_hba, u32 state)
 {
 	struct sas_ha_struct *sas_ha = &hisi_hba->sha;
 	struct asd_sas_port *_sas_port = NULL;
@@ -1553,7 +1552,7 @@ void hisi_sas_controller_reset_done(struct hisi_hba *hisi_hba)
 	clear_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags);
 
 	state = hisi_hba->hw->get_phys_state(hisi_hba);
-	hisi_sas_rescan_topology(hisi_hba, hisi_hba->phy_state, state);
+	hisi_sas_rescan_topology(hisi_hba, state);
 }
 EXPORT_SYMBOL_GPL(hisi_sas_controller_reset_done);
 
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index b01ccb38b00a..8e96a257e439 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3498,8 +3498,8 @@ static int write_gpio_v2_hw(struct hisi_hba *hisi_hba, u8 reg_type,
 	return 0;
 }
 
-static int wait_cmds_complete_timeout_v2_hw(struct hisi_hba *hisi_hba,
-					    int delay_ms, int timeout_ms)
+static void wait_cmds_complete_timeout_v2_hw(struct hisi_hba *hisi_hba,
+					     int delay_ms, int timeout_ms)
 {
 	struct device *dev = hisi_hba->dev;
 	int entries, entries_old = 0, time;
@@ -3513,12 +3513,13 @@ static int wait_cmds_complete_timeout_v2_hw(struct hisi_hba *hisi_hba,
 		msleep(delay_ms);
 	}
 
-	if (time >= timeout_ms)
-		return -ETIMEDOUT;
+	if (time >= timeout_ms) {
+		dev_dbg(dev, "Wait commands complete timeout!\n");
+		return;
+	}
 
 	dev_dbg(dev, "wait commands complete %dms\n", time);
 
-	return 0;
 }
 
 static struct device_attribute *host_attrs_v2_hw[] = {
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 0a159df87d7b..e4db85b8af3e 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2576,8 +2576,8 @@ static int write_gpio_v3_hw(struct hisi_hba *hisi_hba, u8 reg_type,
 	return 0;
 }
 
-static int wait_cmds_complete_timeout_v3_hw(struct hisi_hba *hisi_hba,
-					    int delay_ms, int timeout_ms)
+static void wait_cmds_complete_timeout_v3_hw(struct hisi_hba *hisi_hba,
+					     int delay_ms, int timeout_ms)
 {
 	struct device *dev = hisi_hba->dev;
 	int entries, entries_old = 0, time;
@@ -2591,12 +2591,12 @@ static int wait_cmds_complete_timeout_v3_hw(struct hisi_hba *hisi_hba,
 		msleep(delay_ms);
 	}
 
-	if (time >= timeout_ms)
-		return -ETIMEDOUT;
+	if (time >= timeout_ms) {
+		dev_dbg(dev, "Wait commands complete timeout!\n");
+		return;
+	}
 
 	dev_dbg(dev, "wait commands complete %dms\n", time);
-
-	return 0;
 }
 
 static ssize_t intr_conv_v3_hw_show(struct device *dev,
@@ -2877,14 +2877,11 @@ static const struct hisi_sas_debugfs_reg debugfs_ras_reg = {
 
 static void debugfs_snapshot_prepare_v3_hw(struct hisi_hba *hisi_hba)
 {
-	struct device *dev = hisi_hba->dev;
-
 	set_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
 
 	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE, 0);
 
-	if (wait_cmds_complete_timeout_v3_hw(hisi_hba, 100, 5000) == -ETIMEDOUT)
-		dev_dbg(dev, "Wait commands complete timeout!\n");
+	wait_cmds_complete_timeout_v3_hw(hisi_hba, 100, 5000);
 
 	hisi_sas_kill_tasklets(hisi_hba);
 }
-- 
2.17.1

[PATCH 11/13] scsi: hisi_sas: Add hisi_sas_debugfs_alloc() to centralise allocation

[John Garry]

From: Luo Jiaxing <luojiaxing@huawei.com>

We extract the code of memory allocate and construct an new function for
it. We think it's convenient for subsequent optimization.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 102 +++++++++++++++-----------
 1 file changed, 58 insertions(+), 44 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index b96732493137..e7056bbad7d7 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -3307,27 +3307,44 @@ void hisi_sas_debugfs_work_handler(struct work_struct *work)
 }
 EXPORT_SYMBOL_GPL(hisi_sas_debugfs_work_handler);
 
-void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
+void hisi_sas_debugfs_release(struct hisi_hba *hisi_hba)
+{
+	struct device *dev = hisi_hba->dev;
+	int i;
+
+	devm_kfree(dev, hisi_hba->debugfs_iost_cache);
+	devm_kfree(dev, hisi_hba->debugfs_itct_cache);
+	devm_kfree(dev, hisi_hba->debugfs_iost);
+
+	for (i = 0; i < hisi_hba->queue_count; i++)
+		devm_kfree(dev, hisi_hba->debugfs_cmd_hdr[i]);
+
+	for (i = 0; i < hisi_hba->queue_count; i++)
+		devm_kfree(dev, hisi_hba->debugfs_complete_hdr[i]);
+
+	for (i = 0; i < DEBUGFS_REGS_NUM; i++)
+		devm_kfree(dev, hisi_hba->debugfs_regs[i]);
+
+	for (i = 0; i < hisi_hba->n_phy; i++)
+		devm_kfree(dev, hisi_hba->debugfs_port_reg[i]);
+}
+
+int hisi_sas_debugfs_alloc(struct hisi_hba *hisi_hba)
 {
-	int max_command_entries = HISI_SAS_MAX_COMMANDS;
 	const struct hisi_sas_hw *hw = hisi_hba->hw;
 	struct device *dev = hisi_hba->dev;
-	int p, i, c, d;
+	int p, c, d;
 	size_t sz;
 
-	hisi_hba->debugfs_dir = debugfs_create_dir(dev_name(dev),
-						   hisi_sas_debugfs_dir);
-	debugfs_create_file("trigger_dump", 0600,
-			    hisi_hba->debugfs_dir,
-			    hisi_hba,
-			    &hisi_sas_debugfs_trigger_dump_fops);
+	hisi_hba->debugfs_dump_dentry =
+			debugfs_create_dir("dump", hisi_hba->debugfs_dir);
 
 	sz = hw->debugfs_reg_array[DEBUGFS_GLOBAL]->count * 4;
 	hisi_hba->debugfs_regs[DEBUGFS_GLOBAL] =
 				devm_kmalloc(dev, sz, GFP_KERNEL);
 
 	if (!hisi_hba->debugfs_regs[DEBUGFS_GLOBAL])
-		goto fail_global;
+		goto fail;
 
 	sz = hw->debugfs_reg_port->count * 4;
 	for (p = 0; p < hisi_hba->n_phy; p++) {
@@ -3335,7 +3352,7 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 			devm_kmalloc(dev, sz, GFP_KERNEL);
 
 		if (!hisi_hba->debugfs_port_reg[p])
-			goto fail_port;
+			goto fail;
 	}
 
 	sz = hw->debugfs_reg_array[DEBUGFS_AXI]->count * 4;
@@ -3343,14 +3360,14 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 		devm_kmalloc(dev, sz, GFP_KERNEL);
 
 	if (!hisi_hba->debugfs_regs[DEBUGFS_AXI])
-		goto fail_axi;
+		goto fail;
 
 	sz = hw->debugfs_reg_array[DEBUGFS_RAS]->count * 4;
 	hisi_hba->debugfs_regs[DEBUGFS_RAS] =
 		devm_kmalloc(dev, sz, GFP_KERNEL);
 
 	if (!hisi_hba->debugfs_regs[DEBUGFS_RAS])
-		goto fail_ras;
+		goto fail;
 
 	sz = hw->complete_hdr_size * HISI_SAS_QUEUE_SLOTS;
 	for (c = 0; c < hisi_hba->queue_count; c++) {
@@ -3358,7 +3375,7 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 			devm_kmalloc(dev, sz, GFP_KERNEL);
 
 		if (!hisi_hba->debugfs_complete_hdr[c])
-			goto fail_cq;
+			goto fail;
 	}
 
 	sz = sizeof(struct hisi_sas_cmd_hdr) * HISI_SAS_QUEUE_SLOTS;
@@ -3367,60 +3384,57 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 			devm_kmalloc(dev, sz, GFP_KERNEL);
 
 		if (!hisi_hba->debugfs_cmd_hdr[d])
-			goto fail_iost_dq;
+			goto fail;
 	}
 
-	sz = max_command_entries * sizeof(struct hisi_sas_iost);
+	sz = HISI_SAS_MAX_COMMANDS * sizeof(struct hisi_sas_iost);
 
 	hisi_hba->debugfs_iost = devm_kmalloc(dev, sz, GFP_KERNEL);
 	if (!hisi_hba->debugfs_iost)
-		goto fail_iost_dq;
+		goto fail;
 
 	sz = HISI_SAS_IOST_ITCT_CACHE_NUM *
 	     sizeof(struct hisi_sas_iost_itct_cache);
 
 	hisi_hba->debugfs_iost_cache = devm_kmalloc(dev, sz, GFP_KERNEL);
 	if (!hisi_hba->debugfs_iost_cache)
-		goto fail_iost_cache;
+		goto fail;
 
 	sz = HISI_SAS_IOST_ITCT_CACHE_NUM *
 	     sizeof(struct hisi_sas_iost_itct_cache);
 
 	hisi_hba->debugfs_itct_cache = devm_kmalloc(dev, sz, GFP_KERNEL);
 	if (!hisi_hba->debugfs_itct_cache)
-		goto fail_itct_cache;
+		goto fail;
 
 	/* New memory allocation must be locate before itct */
 	sz = HISI_SAS_MAX_ITCT_ENTRIES * sizeof(struct hisi_sas_itct);
 
 	hisi_hba->debugfs_itct = devm_kmalloc(dev, sz, GFP_KERNEL);
 	if (!hisi_hba->debugfs_itct)
-		goto fail_itct;
+		goto fail;
 
-	return;
-fail_itct:
-	devm_kfree(dev, hisi_hba->debugfs_iost_cache);
-fail_itct_cache:
-	devm_kfree(dev, hisi_hba->debugfs_iost_cache);
-fail_iost_cache:
-	devm_kfree(dev, hisi_hba->debugfs_iost);
-fail_iost_dq:
-	for (i = 0; i < d; i++)
-		devm_kfree(dev, hisi_hba->debugfs_cmd_hdr[i]);
-fail_cq:
-	for (i = 0; i < c; i++)
-		devm_kfree(dev, hisi_hba->debugfs_complete_hdr[i]);
-	devm_kfree(dev, hisi_hba->debugfs_regs[DEBUGFS_RAS]);
-fail_ras:
-	devm_kfree(dev, hisi_hba->debugfs_regs[DEBUGFS_AXI]);
-fail_axi:
-fail_port:
-	for (i = 0; i < p; i++)
-		devm_kfree(dev, hisi_hba->debugfs_port_reg[i]);
-	devm_kfree(dev, hisi_hba->debugfs_regs[DEBUGFS_GLOBAL]);
-fail_global:
-	debugfs_remove_recursive(hisi_hba->debugfs_dir);
-	dev_dbg(dev, "failed to init debugfs!\n");
+	return 0;
+fail:
+	hisi_sas_debugfs_release(hisi_hba);
+	return -ENOMEM;
+}
+
+void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
+{
+	struct device *dev = hisi_hba->dev;
+
+	hisi_hba->debugfs_dir = debugfs_create_dir(dev_name(dev),
+						   hisi_sas_debugfs_dir);
+	debugfs_create_file("trigger_dump", 0600,
+			    hisi_hba->debugfs_dir,
+			    hisi_hba,
+			    &hisi_sas_debugfs_trigger_dump_fops);
+
+	if (hisi_sas_debugfs_alloc(hisi_hba)) {
+		debugfs_remove_recursive(hisi_hba->debugfs_dir);
+		dev_dbg(dev, "failed to init debugfs!\n");
+	}
 }
 EXPORT_SYMBOL_GPL(hisi_sas_debugfs_init);
 
-- 
2.17.1

[PATCH 12/13] scsi: hisi_sas: Add BIST support for phy loopback

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

Add BIST (built in self test) support for phy loopback.

Through the new debugfs interface, the user can configure loopback
mode/linkrate/phy id/code mode before enabling it. And also user can
enable/disable BIST function.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |  10 +
 drivers/scsi/hisi_sas/hisi_sas_main.c  | 407 +++++++++++++++++++++++++
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 126 ++++++++
 3 files changed, 543 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index ccbe4563402a..720c4d6be939 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -310,6 +310,7 @@ struct hisi_sas_hw {
 					   int delay_ms, int timeout_ms);
 	void (*snapshot_prepare)(struct hisi_hba *hisi_hba);
 	void (*snapshot_restore)(struct hisi_hba *hisi_hba);
+	int (*set_bist)(struct hisi_hba *hisi_hba, bool enable);
 	void (*read_iost_itct_cache)(struct hisi_hba *hisi_hba,
 				     enum hisi_sas_debugfs_cache_type type,
 				     u32 *cache);
@@ -391,6 +392,14 @@ struct hisi_hba {
 	int cq_nvecs;
 	unsigned int *reply_map;
 
+	/* bist */
+	enum sas_linkrate debugfs_bist_linkrate;
+	int debugfs_bist_code_mode;
+	int debugfs_bist_phy_no;
+	int debugfs_bist_mode;
+	u32 debugfs_bist_cnt;
+	int debugfs_bist_enable;
+
 	/* debugfs memories */
 	/* Put Global AXI and RAS Register into register array */
 	u32 *debugfs_regs[DEBUGFS_REGS_NUM];
@@ -404,6 +413,7 @@ struct hisi_hba {
 
 	struct dentry *debugfs_dir;
 	struct dentry *debugfs_dump_dentry;
+	struct dentry *debugfs_bist_dentry;
 	bool debugfs_snapshot;
 };
 
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index e7056bbad7d7..04cbc54be387 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -3294,6 +3294,382 @@ static const struct file_operations hisi_sas_debugfs_trigger_dump_fops = {
 	.owner = THIS_MODULE,
 };
 
+enum {
+	HISI_SAS_BIST_LOOPBACK_MODE_DIGITAL = 0,
+	HISI_SAS_BIST_LOOPBACK_MODE_SERDES,
+	HISI_SAS_BIST_LOOPBACK_MODE_REMOTE,
+};
+
+enum {
+	HISI_SAS_BIST_CODE_MODE_PRBS7 = 0,
+	HISI_SAS_BIST_CODE_MODE_PRBS23,
+	HISI_SAS_BIST_CODE_MODE_PRBS31,
+	HISI_SAS_BIST_CODE_MODE_JTPAT,
+	HISI_SAS_BIST_CODE_MODE_CJTPAT,
+	HISI_SAS_BIST_CODE_MODE_SCRAMBED_0,
+	HISI_SAS_BIST_CODE_MODE_TRAIN,
+	HISI_SAS_BIST_CODE_MODE_TRAIN_DONE,
+	HISI_SAS_BIST_CODE_MODE_HFTP,
+	HISI_SAS_BIST_CODE_MODE_MFTP,
+	HISI_SAS_BIST_CODE_MODE_LFTP,
+	HISI_SAS_BIST_CODE_MODE_FIXED_DATA,
+};
+
+static const struct {
+	int		value;
+	char		*name;
+} hisi_sas_debugfs_loop_linkrate[] = {
+	{ SAS_LINK_RATE_1_5_GBPS, "1.5 Gbit" },
+	{ SAS_LINK_RATE_3_0_GBPS, "3.0 Gbit" },
+	{ SAS_LINK_RATE_6_0_GBPS, "6.0 Gbit" },
+	{ SAS_LINK_RATE_12_0_GBPS, "12.0 Gbit" },
+};
+
+static int hisi_sas_debugfs_bist_linkrate_show(struct seq_file *s, void *p)
+{
+	struct hisi_hba *hisi_hba = s->private;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_linkrate); i++) {
+		int match = (hisi_hba->debugfs_bist_linkrate ==
+			     hisi_sas_debugfs_loop_linkrate[i].value);
+
+		seq_printf(s, "%s%s%s ", match ? "[" : "",
+			   hisi_sas_debugfs_loop_linkrate[i].name,
+			   match ? "]" : "");
+	}
+	seq_puts(s, "\n");
+
+	return 0;
+}
+
+static ssize_t hisi_sas_debugfs_bist_linkrate_write(struct file *filp,
+						    const char __user *buf,
+						    size_t count, loff_t *ppos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_hba *hisi_hba = m->private;
+	char kbuf[16] = {}, *pkbuf;
+	bool found = false;
+	int i;
+
+	if (hisi_hba->debugfs_bist_enable)
+		return -EPERM;
+
+	if (count >= sizeof(kbuf))
+		return -EOVERFLOW;
+
+	if (copy_from_user(kbuf, buf, count))
+		return -EINVAL;
+
+	pkbuf = strstrip(kbuf);
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_linkrate); i++) {
+		if (!strncmp(hisi_sas_debugfs_loop_linkrate[i].name,
+			     pkbuf, 16)) {
+			hisi_hba->debugfs_bist_linkrate =
+				hisi_sas_debugfs_loop_linkrate[i].value;
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	return count;
+}
+
+static int hisi_sas_debugfs_bist_linkrate_open(struct inode *inode,
+					       struct file *filp)
+{
+	return single_open(filp, hisi_sas_debugfs_bist_linkrate_show,
+			   inode->i_private);
+}
+
+static const struct file_operations hisi_sas_debugfs_bist_linkrate_ops = {
+	.open = hisi_sas_debugfs_bist_linkrate_open,
+	.read = seq_read,
+	.write = hisi_sas_debugfs_bist_linkrate_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static const struct {
+	int		value;
+	char		*name;
+} hisi_sas_debugfs_loop_code_mode[] = {
+	{ HISI_SAS_BIST_CODE_MODE_PRBS7, "PRBS7" },
+	{ HISI_SAS_BIST_CODE_MODE_PRBS23, "PRBS23" },
+	{ HISI_SAS_BIST_CODE_MODE_PRBS31, "PRBS31" },
+	{ HISI_SAS_BIST_CODE_MODE_JTPAT, "JTPAT" },
+	{ HISI_SAS_BIST_CODE_MODE_CJTPAT, "CJTPAT" },
+	{ HISI_SAS_BIST_CODE_MODE_SCRAMBED_0, "SCRAMBED_0" },
+	{ HISI_SAS_BIST_CODE_MODE_TRAIN, "TRAIN" },
+	{ HISI_SAS_BIST_CODE_MODE_TRAIN_DONE, "TRAIN_DONE" },
+	{ HISI_SAS_BIST_CODE_MODE_HFTP, "HFTP" },
+	{ HISI_SAS_BIST_CODE_MODE_MFTP, "MFTP" },
+	{ HISI_SAS_BIST_CODE_MODE_LFTP, "LFTP" },
+	{ HISI_SAS_BIST_CODE_MODE_FIXED_DATA, "FIXED_DATA" },
+};
+
+static int hisi_sas_debugfs_bist_code_mode_show(struct seq_file *s, void *p)
+{
+	struct hisi_hba *hisi_hba = s->private;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_code_mode); i++) {
+		int match = (hisi_hba->debugfs_bist_code_mode ==
+			     hisi_sas_debugfs_loop_code_mode[i].value);
+
+		seq_printf(s, "%s%s%s ", match ? "[" : "",
+			   hisi_sas_debugfs_loop_code_mode[i].name,
+			   match ? "]" : "");
+	}
+	seq_puts(s, "\n");
+
+	return 0;
+}
+
+static ssize_t hisi_sas_debugfs_bist_code_mode_write(struct file *filp,
+						     const char __user *buf,
+						     size_t count,
+						     loff_t *ppos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_hba *hisi_hba = m->private;
+	char kbuf[16] = {}, *pkbuf;
+	bool found = false;
+	int i;
+
+	if (hisi_hba->debugfs_bist_enable)
+		return -EPERM;
+
+	if (count >= sizeof(kbuf))
+		return -EINVAL;
+
+	if (copy_from_user(kbuf, buf, count))
+		return -EOVERFLOW;
+
+	pkbuf = strstrip(kbuf);
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_code_mode); i++) {
+		if (!strncmp(hisi_sas_debugfs_loop_code_mode[i].name,
+			     pkbuf, 16)) {
+			hisi_hba->debugfs_bist_code_mode =
+				hisi_sas_debugfs_loop_code_mode[i].value;
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	return count;
+}
+
+static int hisi_sas_debugfs_bist_code_mode_open(struct inode *inode,
+						struct file *filp)
+{
+	return single_open(filp, hisi_sas_debugfs_bist_code_mode_show,
+			   inode->i_private);
+}
+
+static const struct file_operations hisi_sas_debugfs_bist_code_mode_ops = {
+	.open = hisi_sas_debugfs_bist_code_mode_open,
+	.read = seq_read,
+	.write = hisi_sas_debugfs_bist_code_mode_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t hisi_sas_debugfs_bist_phy_write(struct file *filp,
+					       const char __user *buf,
+					       size_t count, loff_t *ppos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_hba *hisi_hba = m->private;
+	unsigned int phy_no;
+	int val;
+
+	if (hisi_hba->debugfs_bist_enable)
+		return -EPERM;
+
+	val = kstrtouint_from_user(buf, count, 0, &phy_no);
+	if (val)
+		return val;
+
+	if (phy_no >= hisi_hba->n_phy)
+		return -EINVAL;
+
+	hisi_hba->debugfs_bist_phy_no = phy_no;
+
+	return count;
+}
+
+static int hisi_sas_debugfs_bist_phy_show(struct seq_file *s, void *p)
+{
+	struct hisi_hba *hisi_hba = s->private;
+
+	seq_printf(s, "%d\n", hisi_hba->debugfs_bist_phy_no);
+
+	return 0;
+}
+
+static int hisi_sas_debugfs_bist_phy_open(struct inode *inode,
+					  struct file *filp)
+{
+	return single_open(filp, hisi_sas_debugfs_bist_phy_show,
+			   inode->i_private);
+}
+
+static const struct file_operations hisi_sas_debugfs_bist_phy_ops = {
+	.open = hisi_sas_debugfs_bist_phy_open,
+	.read = seq_read,
+	.write = hisi_sas_debugfs_bist_phy_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static const struct {
+	int		value;
+	char		*name;
+} hisi_sas_debugfs_loop_modes[] = {
+	{ HISI_SAS_BIST_LOOPBACK_MODE_DIGITAL, "digial" },
+	{ HISI_SAS_BIST_LOOPBACK_MODE_SERDES, "serdes" },
+	{ HISI_SAS_BIST_LOOPBACK_MODE_REMOTE, "remote" },
+};
+
+static int hisi_sas_debugfs_bist_mode_show(struct seq_file *s, void *p)
+{
+	struct hisi_hba *hisi_hba = s->private;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_modes); i++) {
+		int match = (hisi_hba->debugfs_bist_mode ==
+			     hisi_sas_debugfs_loop_modes[i].value);
+
+		seq_printf(s, "%s%s%s ", match ? "[" : "",
+			   hisi_sas_debugfs_loop_modes[i].name,
+			   match ? "]" : "");
+	}
+	seq_puts(s, "\n");
+
+	return 0;
+}
+
+static ssize_t hisi_sas_debugfs_bist_mode_write(struct file *filp,
+						const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_hba *hisi_hba = m->private;
+	char kbuf[16] = {}, *pkbuf;
+	bool found = false;
+	int i;
+
+	if (hisi_hba->debugfs_bist_enable)
+		return -EPERM;
+
+	if (count >= sizeof(kbuf))
+		return -EINVAL;
+
+	if (copy_from_user(kbuf, buf, count))
+		return -EOVERFLOW;
+
+	pkbuf = strstrip(kbuf);
+
+	for (i = 0; i < ARRAY_SIZE(hisi_sas_debugfs_loop_modes); i++) {
+		if (!strncmp(hisi_sas_debugfs_loop_modes[i].name, pkbuf, 16)) {
+			hisi_hba->debugfs_bist_mode =
+				hisi_sas_debugfs_loop_modes[i].value;
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	return count;
+}
+
+static int hisi_sas_debugfs_bist_mode_open(struct inode *inode,
+					   struct file *filp)
+{
+	return single_open(filp, hisi_sas_debugfs_bist_mode_show,
+			   inode->i_private);
+}
+
+static const struct file_operations hisi_sas_debugfs_bist_mode_ops = {
+	.open = hisi_sas_debugfs_bist_mode_open,
+	.read = seq_read,
+	.write = hisi_sas_debugfs_bist_mode_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t hisi_sas_debugfs_bist_enable_write(struct file *filp,
+						  const char __user *buf,
+						  size_t count, loff_t *ppos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_hba *hisi_hba = m->private;
+	unsigned int enable;
+	int val;
+
+	val = kstrtouint_from_user(buf, count, 0, &enable);
+	if (val)
+		return val;
+
+	if (enable > 1)
+		return -EINVAL;
+
+	if (enable == hisi_hba->debugfs_bist_enable)
+		return count;
+
+	if (!hisi_hba->hw->set_bist)
+		return -EPERM;
+
+	val = hisi_hba->hw->set_bist(hisi_hba, enable);
+	if (val < 0)
+		return val;
+
+	hisi_hba->debugfs_bist_enable = enable;
+
+	return count;
+}
+
+static int hisi_sas_debugfs_bist_enable_show(struct seq_file *s, void *p)
+{
+	struct hisi_hba *hisi_hba = s->private;
+
+	seq_printf(s, "%d\n", hisi_hba->debugfs_bist_enable);
+
+	return 0;
+}
+
+static int hisi_sas_debugfs_bist_enable_open(struct inode *inode,
+					     struct file *filp)
+{
+	return single_open(filp, hisi_sas_debugfs_bist_enable_show,
+			   inode->i_private);
+}
+
+static const struct file_operations hisi_sas_debugfs_bist_enable_ops = {
+	.open = hisi_sas_debugfs_bist_enable_open,
+	.read = seq_read,
+	.write = hisi_sas_debugfs_bist_enable_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
 void hisi_sas_debugfs_work_handler(struct work_struct *work)
 {
 	struct hisi_hba *hisi_hba =
@@ -3420,6 +3796,34 @@ int hisi_sas_debugfs_alloc(struct hisi_hba *hisi_hba)
 	return -ENOMEM;
 }
 
+void hisi_sas_debugfs_bist_init(struct hisi_hba *hisi_hba)
+{
+	hisi_hba->debugfs_bist_dentry =
+			debugfs_create_dir("bist", hisi_hba->debugfs_dir);
+	debugfs_create_file("link_rate", 0600,
+			    hisi_hba->debugfs_bist_dentry, hisi_hba,
+			    &hisi_sas_debugfs_bist_linkrate_ops);
+
+	debugfs_create_file("code_mode", 0600,
+			    hisi_hba->debugfs_bist_dentry, hisi_hba,
+			    &hisi_sas_debugfs_bist_code_mode_ops);
+
+	debugfs_create_file("phy_id", 0600, hisi_hba->debugfs_bist_dentry,
+			    hisi_hba, &hisi_sas_debugfs_bist_phy_ops);
+
+	debugfs_create_u32("cnt", 0600, hisi_hba->debugfs_bist_dentry,
+			   &hisi_hba->debugfs_bist_cnt);
+
+	debugfs_create_file("loopback_mode", 0600,
+			    hisi_hba->debugfs_bist_dentry,
+			    hisi_hba, &hisi_sas_debugfs_bist_mode_ops);
+
+	debugfs_create_file("enable", 0600, hisi_hba->debugfs_bist_dentry,
+			    hisi_hba, &hisi_sas_debugfs_bist_enable_ops);
+
+	hisi_hba->debugfs_bist_linkrate = SAS_LINK_RATE_1_5_GBPS;
+}
+
 void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 {
 	struct device *dev = hisi_hba->dev;
@@ -3431,6 +3835,9 @@ void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 			    hisi_hba,
 			    &hisi_sas_debugfs_trigger_dump_fops);
 
+	/* create bist structures */
+	hisi_sas_debugfs_bist_init(hisi_hba);
+
 	if (hisi_sas_debugfs_alloc(hisi_hba)) {
 		debugfs_remove_recursive(hisi_hba->debugfs_dir);
 		dev_dbg(dev, "failed to init debugfs!\n");
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index e4db85b8af3e..cb8d087762db 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -191,12 +191,30 @@
 #define PHY_CFG_PHY_RST_OFF		3
 #define PHY_CFG_PHY_RST_MSK		(0x1 << PHY_CFG_PHY_RST_OFF)
 #define PROG_PHY_LINK_RATE		(PORT_BASE + 0x8)
+#define CFG_PROG_PHY_LINK_RATE_OFF	8
+#define CFG_PROG_PHY_LINK_RATE_MSK	(0xf << CFG_PROG_PHY_LINK_RATE_OFF)
 #define PHY_CTRL			(PORT_BASE + 0x14)
 #define PHY_CTRL_RESET_OFF		0
 #define PHY_CTRL_RESET_MSK		(0x1 << PHY_CTRL_RESET_OFF)
 #define CMD_HDR_PIR_OFF			8
 #define CMD_HDR_PIR_MSK			(0x1 << CMD_HDR_PIR_OFF)
 #define SERDES_CFG			(PORT_BASE + 0x1c)
+#define CFG_ALOS_CHK_DISABLE_OFF	9
+#define CFG_ALOS_CHK_DISABLE_MSK	(0x1 << CFG_ALOS_CHK_DISABLE_OFF)
+#define SAS_PHY_BIST_CTRL		(PORT_BASE + 0x2c)
+#define CFG_BIST_MODE_SEL_OFF		0
+#define CFG_BIST_MODE_SEL_MSK		(0xf << CFG_BIST_MODE_SEL_OFF)
+#define CFG_LOOP_TEST_MODE_OFF		14
+#define CFG_LOOP_TEST_MODE_MSK		(0x3 << CFG_LOOP_TEST_MODE_OFF)
+#define CFG_RX_BIST_EN_OFF		16
+#define CFG_RX_BIST_EN_MSK		(0x1 << CFG_RX_BIST_EN_OFF)
+#define CFG_TX_BIST_EN_OFF		17
+#define CFG_TX_BIST_EN_MSK		(0x1 << CFG_TX_BIST_EN_OFF)
+#define CFG_BIST_TEST_OFF		18
+#define CFG_BIST_TEST_MSK		(0x1 << CFG_BIST_TEST_OFF)
+#define SAS_PHY_BIST_CODE		(PORT_BASE + 0x30)
+#define SAS_PHY_BIST_CODE1		(PORT_BASE + 0x34)
+#define SAS_BIST_ERR_CNT		(PORT_BASE + 0x38)
 #define SL_CFG				(PORT_BASE + 0x84)
 #define AIP_LIMIT			(PORT_BASE + 0x90)
 #define SL_CONTROL			(PORT_BASE + 0x94)
@@ -2923,6 +2941,113 @@ static void read_iost_itct_cache_v3_hw(struct hisi_hba *hisi_hba,
 		buf[i] = hisi_sas_read32(hisi_hba, TAB_DFX);
 }
 
+static void hisi_sas_bist_test_prep_v3_hw(struct hisi_hba *hisi_hba)
+{
+	u32 reg_val;
+	int phy_id = hisi_hba->debugfs_bist_phy_no;
+
+	/* disable PHY */
+	hisi_sas_phy_enable(hisi_hba, phy_id, 0);
+
+	/* disable ALOS */
+	reg_val = hisi_sas_phy_read32(hisi_hba, phy_id, SERDES_CFG);
+	reg_val |= CFG_ALOS_CHK_DISABLE_MSK;
+	hisi_sas_phy_write32(hisi_hba, phy_id, SERDES_CFG, reg_val);
+}
+
+static void hisi_sas_bist_test_restore_v3_hw(struct hisi_hba *hisi_hba)
+{
+	u32 reg_val;
+	int phy_id = hisi_hba->debugfs_bist_phy_no;
+
+	/* disable loopback */
+	reg_val = hisi_sas_phy_read32(hisi_hba, phy_id, SAS_PHY_BIST_CTRL);
+	reg_val &= ~(CFG_RX_BIST_EN_MSK | CFG_TX_BIST_EN_MSK |
+		     CFG_BIST_TEST_MSK);
+	hisi_sas_phy_write32(hisi_hba, phy_id, SAS_PHY_BIST_CTRL, reg_val);
+
+	/* enable ALOS */
+	reg_val = hisi_sas_phy_read32(hisi_hba, phy_id, SERDES_CFG);
+	reg_val &= ~CFG_ALOS_CHK_DISABLE_MSK;
+	hisi_sas_phy_write32(hisi_hba, phy_id, SERDES_CFG, reg_val);
+
+	/* restore the linkrate */
+	reg_val = hisi_sas_phy_read32(hisi_hba, phy_id, PROG_PHY_LINK_RATE);
+	/* init OOB link rate as 1.5 Gbits */
+	reg_val &= ~CFG_PROG_PHY_LINK_RATE_MSK;
+	reg_val |= (0x8 << CFG_PROG_PHY_LINK_RATE_OFF);
+	hisi_sas_phy_write32(hisi_hba, phy_id, PROG_PHY_LINK_RATE, reg_val);
+
+	/* enable PHY */
+	hisi_sas_phy_enable(hisi_hba, phy_id, 1);
+}
+
+#define SAS_PHY_BIST_CODE_INIT	0x1
+#define SAS_PHY_BIST_CODE1_INIT	0X80
+static int debugfs_set_bist_v3_hw(struct hisi_hba *hisi_hba, bool enable)
+{
+	u32 reg_val, mode_tmp;
+	u32 linkrate = hisi_hba->debugfs_bist_linkrate;
+	u32 phy_id = hisi_hba->debugfs_bist_phy_no;
+	u32 code_mode = hisi_hba->debugfs_bist_code_mode;
+	u32 path_mode = hisi_hba->debugfs_bist_mode;
+	struct device *dev = hisi_hba->dev;
+
+	dev_info(dev, "BIST info:linkrate=%d phy_id=%d code_mode=%d path_mode=%d\n",
+		 linkrate, phy_id, code_mode, path_mode);
+	mode_tmp = path_mode ? 2 : 1;
+	if (enable) {
+		/* some preparations before bist test */
+		hisi_sas_bist_test_prep_v3_hw(hisi_hba);
+
+		/* set linkrate of bit test*/
+		reg_val = hisi_sas_phy_read32(hisi_hba, phy_id,
+					      PROG_PHY_LINK_RATE);
+		reg_val &= ~CFG_PROG_PHY_LINK_RATE_MSK;
+		reg_val |= (linkrate << CFG_PROG_PHY_LINK_RATE_OFF);
+		hisi_sas_phy_write32(hisi_hba, phy_id,
+				     PROG_PHY_LINK_RATE, reg_val);
+
+		/* set code mode of bit test */
+		reg_val = hisi_sas_phy_read32(hisi_hba, phy_id,
+					      SAS_PHY_BIST_CTRL);
+		reg_val &= ~(CFG_BIST_MODE_SEL_MSK |
+				CFG_LOOP_TEST_MODE_MSK |
+				CFG_RX_BIST_EN_MSK |
+				CFG_TX_BIST_EN_MSK |
+				CFG_BIST_TEST_MSK);
+		reg_val |= ((code_mode << CFG_BIST_MODE_SEL_OFF) |
+			    (mode_tmp << CFG_LOOP_TEST_MODE_OFF) |
+			    CFG_BIST_TEST_MSK);
+		hisi_sas_phy_write32(hisi_hba, phy_id,
+				     SAS_PHY_BIST_CTRL, reg_val);
+
+		mdelay(100);
+		reg_val |= (CFG_RX_BIST_EN_MSK | CFG_TX_BIST_EN_MSK);
+		hisi_sas_phy_write32(hisi_hba, phy_id,
+				     SAS_PHY_BIST_CTRL, reg_val);
+
+		/* set the bist init value */
+		hisi_sas_phy_write32(hisi_hba, phy_id,
+				     SAS_PHY_BIST_CODE,
+				     SAS_PHY_BIST_CODE_INIT);
+		hisi_sas_phy_write32(hisi_hba, phy_id,
+				     SAS_PHY_BIST_CODE1,
+				     SAS_PHY_BIST_CODE1_INIT);
+
+		/* clear error bit */
+		mdelay(100);
+		hisi_sas_phy_read32(hisi_hba, phy_id, SAS_BIST_ERR_CNT);
+	} else {
+		/* disable bist test and recover it */
+		hisi_hba->debugfs_bist_cnt += hisi_sas_phy_read32(hisi_hba,
+				phy_id, SAS_BIST_ERR_CNT);
+		hisi_sas_bist_test_restore_v3_hw(hisi_hba);
+	}
+
+	return 0;
+}
+
 static struct scsi_host_template sht_v3_hw = {
 	.name			= DRV_NAME,
 	.module			= THIS_MODULE,
@@ -2977,6 +3102,7 @@ static const struct hisi_sas_hw hisi_sas_v3_hw = {
 	.snapshot_prepare = debugfs_snapshot_prepare_v3_hw,
 	.snapshot_restore = debugfs_snapshot_restore_v3_hw,
 	.read_iost_itct_cache = read_iost_itct_cache_v3_hw,
+	.set_bist = debugfs_set_bist_v3_hw,
 };
 
 static struct Scsi_Host *
-- 
2.17.1

[PATCH 13/13] scsi: hisi_sas: Fix the conflict between device gone and host reset

[John Garry]

From: Xiang Chen <chenxiang66@hisilicon.com>

When device gone, it will check whether it is during reset, if not, it
will send internal task abort. Before internal task abort returned, reset
begins, and it will check whether SAS_PHY_UNUSED is set, if not, it will
call hisi_sas_init_device(), but at that time domain_device may already
be freed or part of it is freed, so it may referenece null pointer in
hisi_sas_init_device(). It may occur as follows:
    thread0				thread1
hisi_sas_dev_gone()
    check whether in RESET(no)
    internal task abort
				    reset prep
				    soft_reset
				    ... (part of reset_done)
    internal task abort failed
    release resource anyway
    clear_itct
    device->lldd_dev=NULL
				    hisi_sas_reset_init_all_device
					check sas_dev->dev_type is SAS_PHY_UNUSED and
					!device
    set dev_type SAS_PHY_UNUSED
    sas_free_device
					hisi_sas_init_device
					...

Semaphore hisi_hba.sema is used to sync the processes of device gone and
host reset.

To solve the issue, expand the scope that semaphore protects and let
them never occur together.

And also some places will check whether domain_device is NULL to judge
whether the device is gone. So when device gone, need to clear
sas_dev->sas_device.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 04cbc54be387..a7b3d9d38fdc 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1049,21 +1049,22 @@ static void hisi_sas_dev_gone(struct domain_device *device)
 	dev_info(dev, "dev[%d:%x] is gone\n",
 		 sas_dev->device_id, sas_dev->dev_type);
 
+	down(&hisi_hba->sem);
 	if (!test_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags)) {
 		hisi_sas_internal_task_abort(hisi_hba, device,
 					     HISI_SAS_INT_ABT_DEV, 0);
 
 		hisi_sas_dereg_device(hisi_hba, device);
 
-		down(&hisi_hba->sem);
 		hisi_hba->hw->clear_itct(hisi_hba, sas_dev);
-		up(&hisi_hba->sem);
 		device->lldd_dev = NULL;
 	}
 
 	if (hisi_hba->hw->free_device)
 		hisi_hba->hw->free_device(sas_dev);
 	sas_dev->dev_type = SAS_PHY_UNUSED;
+	sas_dev->sas_device = NULL;
+	up(&hisi_hba->sem);
 }
 
 static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
@@ -1543,11 +1544,11 @@ void hisi_sas_controller_reset_done(struct hisi_hba *hisi_hba)
 	msleep(1000);
 	hisi_sas_refresh_port_id(hisi_hba);
 	clear_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
-	up(&hisi_hba->sem);
 
 	if (hisi_hba->reject_stp_links_msk)
 		hisi_sas_terminate_stp_reject(hisi_hba);
 	hisi_sas_reset_init_all_devices(hisi_hba);
+	up(&hisi_hba->sem);
 	scsi_unblock_requests(shost);
 	clear_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags);
 
-- 
2.17.1

Re: [PATCH 00/13] hisi_sas: Some misc patches

[Martin K. Petersen]

John,

> This patchset includes support for some more minor features, a bit of
> tidying, and a few patches to make the driver a bit more robust.

Applied to 5.4/scsi-queue, thanks.

-- 
Martin K. Petersen	Oracle Linux Engineering