[PATCH 1/8] scsi: ufs: Flush exception event before suspend

[PATCH 1/8] scsi: ufs: Flush exception event before suspend

[Can Guo]

From: Sayali Lokhande <sayalil@codeaurora.org>

Exception event can be raised by the device when system
suspend is in progress. This will result in unclocked
register access in exception event handler as clocks will
be turned off during suspend. This change makes sure to flush
exception event handler work in suspend before disabling
clocks to avoid unclocked register access issue.

Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index abd0e6b..10dbc0c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4730,8 +4730,15 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev)
 			 * UFS device needs urgent BKOPs.
 			 */
 			if (!hba->pm_op_in_progress &&
-			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
-				schedule_work(&hba->eeh_work);
+			    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);
+			}
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
 			/* TODO: handle Reject UPIU Response */
@@ -5184,7 +5191,14 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 
 out:
 	ufshcd_scsi_unblock_requests(hba);
-	pm_runtime_put_sync(hba->dev);
+	/*
+	 * 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;
 }
 
@@ -7924,6 +7938,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 			goto enable_gating;
 	}
 
+	flush_work(&hba->eeh_work);
 	ret = ufshcd_link_state_transition(hba, req_link_state, 1);
 	if (ret)
 		goto set_dev_active;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 2/8] scsi: ufs: set load before setting voltage in regulators

[Can Guo]

From: Asutosh Das <asutoshd@codeaurora.org>

This sequence change is required to avoid dips in voltage
during boot-up.

Apparently, this dip is caused because in the original
sequence, the regulators are initialized in lpm mode.
And then when the load is set to high, and more current
is drawn, than is allowed in lpm, the dip is seen.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 10dbc0c..83ae093 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7248,6 +7248,11 @@ static int ufshcd_config_vreg(struct device *dev,
 	name = vreg->name;
 
 	if (regulator_count_voltages(reg) > 0) {
+		uA_load = on ? vreg->max_uA : 0;
+		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
+		if (ret)
+			goto out;
+
 		if (vreg->min_uV && vreg->max_uV) {
 			min_uV = on ? vreg->min_uV : 0;
 			ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
@@ -7258,11 +7263,6 @@ static int ufshcd_config_vreg(struct device *dev,
 				goto out;
 			}
 		}
-
-		uA_load = on ? vreg->max_uA : 0;
-		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
-		if (ret)
-			goto out;
 	}
 out:
 	return ret;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 3/8] scsi: ufs: Remove the check before call setup clock notify vops

[Can Guo]

The functionality of vendor specific ops should be handled properly in
platform specific driver, but should not count on the UFS driver.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 83ae093..bbc2607 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7402,16 +7402,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 	if (list_empty(head))
 		goto out;
 
-	/*
-	 * vendor specific setup_clocks ops may depend on clocks managed by
-	 * this standard driver hence call the vendor specific setup_clocks
-	 * before disabling the clocks managed here.
-	 */
-	if (!on) {
-		ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE);
-		if (ret)
-			return ret;
-	}
+	ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE);
+	if (ret)
+		return ret;
 
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
@@ -7435,16 +7428,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 		}
 	}
 
-	/*
-	 * vendor specific setup_clocks ops may depend on clocks managed by
-	 * this standard driver hence call the vendor specific setup_clocks
-	 * after enabling the clocks managed here.
-	 */
-	if (on) {
-		ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE);
-		if (ret)
-			return ret;
-	}
+	ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE);
+	if (ret)
+		return ret;
 
 out:
 	if (ret) {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 4/8] scsi: ufs-qcom: Adjust bus bandwidth voting and unvoting

[Can Guo]

The bus bandwidth voting is required to be done before the bus clocks
are enabled, and the unvoting is required to be done only after the bus
clocks are disabled.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index c69c29a1c..85d7c17 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -38,7 +38,6 @@ enum {
 
 static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote);
 static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
 static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
 						       u32 clk_cycles);
@@ -674,7 +673,7 @@ static void ufs_qcom_get_speed_mode(struct ufs_pa_layer_attr *p, char *result)
 	}
 }
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
+static int __ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
 {
 	int err = 0;
 
@@ -705,7 +704,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 
 	vote = ufs_qcom_get_bus_vote(host, mode);
 	if (vote >= 0)
-		err = ufs_qcom_set_bus_vote(host, vote);
+		err = __ufs_qcom_set_bus_vote(host, vote);
 	else
 		err = vote;
 
@@ -716,6 +715,35 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 	return err;
 }
 
+static int ufs_qcom_set_bus_vote(struct ufs_hba *hba, bool on)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+	int vote, err;
+
+	/*
+	 * In case ufs_qcom_init() is not yet done, simply ignore.
+	 * This ufs_qcom_set_bus_vote() shall be called from
+	 * ufs_qcom_init() after init is done.
+	 */
+	if (!host)
+		return 0;
+
+	if (on) {
+		vote = host->bus_vote.saved_vote;
+		if (vote == host->bus_vote.min_bw_vote)
+			ufs_qcom_update_bus_bw_vote(host);
+	} else {
+		vote = host->bus_vote.min_bw_vote;
+	}
+
+	err = __ufs_qcom_set_bus_vote(host, vote);
+	if (err)
+		dev_err(hba->dev, "%s: set bus vote failed %d\n",
+				 __func__, err);
+
+	return err;
+}
+
 static ssize_t
 show_ufs_to_mem_max_bus_bw(struct device *dev, struct device_attribute *attr,
 			char *buf)
@@ -792,7 +820,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 	return 0;
 }
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
+static int ufs_qcom_set_bus_vote(struct ufs_hba *host, bool on)
 {
 	return 0;
 }
@@ -1030,8 +1058,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
 				 enum ufs_notify_change_status status)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	int err;
-	int vote = 0;
+	int err = 0;
 
 	/*
 	 * In case ufs_qcom_init() is not yet done, simply ignore.
@@ -1041,28 +1068,21 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
 	if (!host)
 		return 0;
 
-	if (on && (status == POST_CHANGE)) {
+	if (on && (status == PRE_CHANGE)) {
+		err = ufs_qcom_set_bus_vote(hba, true);
+	} else if (on && (status == POST_CHANGE)) {
 		/* enable the device ref clock for HS mode*/
 		if (ufshcd_is_hs_mode(&hba->pwr_info))
 			ufs_qcom_dev_ref_clk_ctrl(host, true);
-		vote = host->bus_vote.saved_vote;
-		if (vote == host->bus_vote.min_bw_vote)
-			ufs_qcom_update_bus_bw_vote(host);
-
 	} else if (!on && (status == PRE_CHANGE)) {
 		if (!ufs_qcom_is_link_active(hba)) {
 			/* disable device ref_clk */
 			ufs_qcom_dev_ref_clk_ctrl(host, false);
 		}
-
-		vote = host->bus_vote.min_bw_vote;
+	} else if (!on && (status == POST_CHANGE)) {
+		err = ufs_qcom_set_bus_vote(hba, false);
 	}
 
-	err = ufs_qcom_set_bus_vote(host, vote);
-	if (err)
-		dev_err(hba->dev, "%s: set bus vote failed %d\n",
-				__func__, err);
-
 	return err;
 }
 
@@ -1238,6 +1258,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
 	ufs_qcom_set_caps(hba);
 	ufs_qcom_advertise_quirks(hba);
 
+	ufs_qcom_set_bus_vote(hba, true);
 	ufs_qcom_setup_clocks(hba, true, POST_CHANGE);
 
 	if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 5/8] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

[Can Guo]

The async version of ufshcd_hold(async == true), which is only called
in queuecommand path as for now, is expected to work in atomic context,
thus it should not sleep or schedule out. When it runs into the condition
that clocks are ON but link is still in hibern8 state, it should bail out
without flushing the clock ungate work.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index bbc2607..e8f7f9d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1518,6 +1518,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */
 		if (ufshcd_can_hibern8_during_gating(hba) &&
 		    ufshcd_is_link_hibern8(hba)) {
+			if (async) {
+				rc = -EAGAIN;
+				hba->clk_gating.active_reqs--;
+				break;
+			}
 			spin_unlock_irqrestore(hba->host->host_lock, flags);
 			flush_work(&hba->clk_gating.ungate_work);
 			spin_lock_irqsave(hba->host->host_lock, flags);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Can Guo]

In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines
the minimum time for which the reference clock is required by device during
transition to LS-MODE or HIBERN8 state. Make this change to reflect the new
requirement by adding delays before turning off the clock.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index cfe3803..990cb48 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -167,6 +167,7 @@ enum attr_idn {
 	QUERY_ATTR_IDN_FFU_STATUS		= 0x14,
 	QUERY_ATTR_IDN_PSA_STATE		= 0x15,
 	QUERY_ATTR_IDN_PSA_DATA_SIZE		= 0x16,
+	QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME	= 0x17,
 };
 
 /* Descriptor idn for Query requests */
@@ -534,6 +535,8 @@ struct ufs_dev_info {
 	u16 wmanufacturerid;
 	/*UFS device Product Name */
 	u8 *model;
+	u16 wspecversion;
+	u32 clk_gating_wait_us;
 };
 
 /**
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e8f7f9d..76beaf9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -91,6 +91,9 @@
 /* default delay of autosuspend: 2000 ms */
 #define RPM_AUTOSUSPEND_DELAY_MS 2000
 
+/* Default value of wait time before gating device ref clock */
+#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
 	({                                                              \
 		int _ret;                                               \
@@ -3281,6 +3284,29 @@ static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
 				      param_offset, param_read_buf, param_size);
 }
 
+static int ufshcd_get_ref_clk_gating_wait(struct ufs_hba *hba)
+{
+	int err = 0;
+	u32 gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
+
+	if (hba->dev_info.wspecversion >= 0x300) {
+		err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME, 0, 0,
+				&gating_wait);
+		if (err)
+			dev_err(hba->dev, "Failed reading bRefClkGatingWait. err = %d, use default %uus\n",
+					 err, gating_wait);
+
+		if (gating_wait == 0) {
+			gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
+			dev_err(hba->dev, "Undefined ref clk gating wait time, use default %uus\n",
+					 gating_wait);
+		}
+	}
+
+	return err;
+}
+
 /**
  * ufshcd_memory_alloc - allocate memory for host memory space data structures
  * @hba: per adapter instance
@@ -6626,6 +6652,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 	dev_info->wmanufacturerid = desc_buf[DEVICE_DESC_PARAM_MANF_ID] << 8 |
 				     desc_buf[DEVICE_DESC_PARAM_MANF_ID + 1];
 
+	/* getting Specification Version in big endian format */
+	dev_info->wspecversion = desc_buf[DEVICE_DESC_PARAM_SPEC_VER] << 8 |
+				      desc_buf[DEVICE_DESC_PARAM_SPEC_VER + 1];
+
 	model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
 	err = ufshcd_read_string_desc(hba, model_index,
 				      &dev_info->model, SD_ASCII_STD);
@@ -7003,6 +7033,8 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
 		goto out;
 	}
 
+	ufshcd_get_ref_clk_gating_wait(hba);
+
 	ufs_fixup_device_setup(hba);
 
 	if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Stanley Chu]

Hi Can,

On Wed, 2020-02-05 at 22:56 -0800, Can Guo wrote:
> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines
> the minimum time for which the reference clock is required by device during
> transition to LS-MODE or HIBERN8 state. Make this change to reflect the new
> requirement by adding delays before turning off the clock.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
> Reviewed-by: Bean Huo <beanhuo@micron.com>

Thanks for the fix.

Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

Re: [PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Can Guo]

On 2020-02-06 15:30, Stanley Chu wrote:
> Hi Can,
> 
> On Wed, 2020-02-05 at 22:56 -0800, Can Guo wrote:
>> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime 
>> defines
>> the minimum time for which the reference clock is required by device 
>> during
>> transition to LS-MODE or HIBERN8 state. Make this change to reflect 
>> the new
>> requirement by adding delays before turning off the clock.
>> 
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
>> Reviewed-by: Bean Huo <beanhuo@micron.com>
> 
> Thanks for the fix.
> 
> Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

Thank you for your review. :)

Can Guo

RE: [PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Avri Altman]

> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines
> the minimum time for which the reference clock is required by device during
> transition to LS-MODE or HIBERN8 state. Make this change to reflect the new
> requirement by adding delays before turning off the clock.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> 
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index cfe3803..990cb48 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -167,6 +167,7 @@ enum attr_idn {
>         QUERY_ATTR_IDN_FFU_STATUS               = 0x14,
>         QUERY_ATTR_IDN_PSA_STATE                = 0x15,
>         QUERY_ATTR_IDN_PSA_DATA_SIZE            = 0x16,
> +       QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME = 0x17,
>  };
> 
>  /* Descriptor idn for Query requests */
> @@ -534,6 +535,8 @@ struct ufs_dev_info {
>         u16 wmanufacturerid;
>         /*UFS device Product Name */
>         u8 *model;
> +       u16 wspecversion;
> +       u32 clk_gating_wait_us;
>  };
> 
>  /**
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e8f7f9d..76beaf9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -91,6 +91,9 @@
>  /* default delay of autosuspend: 2000 ms */
>  #define RPM_AUTOSUSPEND_DELAY_MS 2000
> 
> +/* Default value of wait time before gating device ref clock */
> +#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
> +
>  #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
>         ({                                                              \
>                 int _ret;                                               \
> @@ -3281,6 +3284,29 @@ static inline int
> ufshcd_read_unit_desc_param(struct ufs_hba *hba,
>                                       param_offset, param_read_buf, param_size);
>  }
> 
> +static int ufshcd_get_ref_clk_gating_wait(struct ufs_hba *hba)
> +{
> +       int err = 0;
> +       u32 gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> +
> +       if (hba->dev_info.wspecversion >= 0x300) {
> +               err = ufshcd_query_attr_retry(hba,
> UPIU_QUERY_OPCODE_READ_ATTR,
> +                               QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME, 0, 0,
> +                               &gating_wait);
> +               if (err)
> +                       dev_err(hba->dev, "Failed reading bRefClkGatingWait. err =
> %d, use default %uus\n",
> +                                        err, gating_wait);
> +
> +               if (gating_wait == 0) {
> +                       gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> +                       dev_err(hba->dev, "Undefined ref clk gating wait time, use
> default %uus\n",
> +                                        gating_wait);
> +               }

You forgot to set
hba->dev_info.clk_gating_wait_us = gating_wait

Thanks,
Avri

Re: [PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Can Guo]

On 2020-02-06 15:57, Avri Altman wrote:
>> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime 
>> defines
>> the minimum time for which the reference clock is required by device 
>> during
>> transition to LS-MODE or HIBERN8 state. Make this change to reflect 
>> the new
>> requirement by adding delays before turning off the clock.
>> 
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>> 
>> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
>> index cfe3803..990cb48 100644
>> --- a/drivers/scsi/ufs/ufs.h
>> +++ b/drivers/scsi/ufs/ufs.h
>> @@ -167,6 +167,7 @@ enum attr_idn {
>>         QUERY_ATTR_IDN_FFU_STATUS               = 0x14,
>>         QUERY_ATTR_IDN_PSA_STATE                = 0x15,
>>         QUERY_ATTR_IDN_PSA_DATA_SIZE            = 0x16,
>> +       QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME = 0x17,
>>  };
>> 
>>  /* Descriptor idn for Query requests */
>> @@ -534,6 +535,8 @@ struct ufs_dev_info {
>>         u16 wmanufacturerid;
>>         /*UFS device Product Name */
>>         u8 *model;
>> +       u16 wspecversion;
>> +       u32 clk_gating_wait_us;
>>  };
>> 
>>  /**
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index e8f7f9d..76beaf9 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -91,6 +91,9 @@
>>  /* default delay of autosuspend: 2000 ms */
>>  #define RPM_AUTOSUSPEND_DELAY_MS 2000
>> 
>> +/* Default value of wait time before gating device ref clock */
>> +#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
>> +
>>  #define ufshcd_toggle_vreg(_dev, _vreg, _on)                          
>>  \
>>         ({                                                             
>>  \
>>                 int _ret;                                              
>>  \
>> @@ -3281,6 +3284,29 @@ static inline int
>> ufshcd_read_unit_desc_param(struct ufs_hba *hba,
>>                                       param_offset, param_read_buf, 
>> param_size);
>>  }
>> 
>> +static int ufshcd_get_ref_clk_gating_wait(struct ufs_hba *hba)
>> +{
>> +       int err = 0;
>> +       u32 gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
>> +
>> +       if (hba->dev_info.wspecversion >= 0x300) {
>> +               err = ufshcd_query_attr_retry(hba,
>> UPIU_QUERY_OPCODE_READ_ATTR,
>> +                               
>> QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME, 0, 0,
>> +                               &gating_wait);
>> +               if (err)
>> +                       dev_err(hba->dev, "Failed reading 
>> bRefClkGatingWait. err =
>> %d, use default %uus\n",
>> +                                        err, gating_wait);
>> +
>> +               if (gating_wait == 0) {
>> +                       gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
>> +                       dev_err(hba->dev, "Undefined ref clk gating 
>> wait time, use
>> default %uus\n",
>> +                                        gating_wait);
>> +               }
> 
> You forgot to set
> hba->dev_info.clk_gating_wait_us = gating_wait
> 
> Thanks,
> Avri

oops, shall add it back. Thanks.

Can Guo

[PATCH 7/8] scsi: ufs-qcom: Delay specific time before gate ref clk

[Can Guo]

After enter hibern8, as UFS JEDEC ver 3.0 requires, a specific gating wait
time is required before disable the device reference clock. If it is not
specified, use the old delay.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 85d7c17..39eefa4 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -833,6 +833,8 @@ static int ufs_qcom_bus_register(struct ufs_qcom_host *host)
 
 static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 {
+	unsigned long gating_wait;
+
 	if (host->dev_ref_clk_ctrl_mmio &&
 	    (enable ^ host->is_dev_ref_clk_enabled)) {
 		u32 temp = readl_relaxed(host->dev_ref_clk_ctrl_mmio);
@@ -845,11 +847,25 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 		/*
 		 * If we are here to disable this clock it might be immediately
 		 * after entering into hibern8 in which case we need to make
-		 * sure that device ref_clk is active at least 1us after the
+		 * sure that device ref_clk is active for specific time after
 		 * hibern8 enter.
 		 */
-		if (!enable)
-			udelay(1);
+		if (!enable) {
+			gating_wait = host->hba->dev_info.clk_gating_wait_us;
+			if (!gating_wait) {
+				udelay(1);
+			} else {
+				/*
+				 * bRefClkGatingWaitTime defines the minimum
+				 * time for which the reference clock is
+				 * required by device during transition from
+				 * HS-MODE to LS-MODE or HIBERN8 state. Give it
+				 * more time to be on the safe side.
+				 */
+				gating_wait += 10;
+				usleep_range(gating_wait, gating_wait + 10);
+			}
+		}
 
 		writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 8/8] scsi: ufs: Select INITIAL adapt for HS Gear4

[Can Guo]

ADAPT is added specifically for HS Gear4 mode only, select INITIAL adapt
before do power mode change to G4 and select no adapt before switch to
non-G4 modes.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 76beaf9..1fe0a97 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4069,6 +4069,17 @@ static int ufshcd_change_power_mode(struct ufs_hba *hba,
 		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES),
 						pwr_mode->hs_rate);
 
+	if (hba->ufs_version >= UFSHCI_VERSION_30) {
+		if (pwr_mode->gear_tx == UFS_HS_G4)
+			/* INITIAL ADAPT */
+			ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXHSADAPTTYPE),
+					PA_INITIAL_ADAPT);
+		else
+			/* NO ADAPT */
+			ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXHSADAPTTYPE),
+					PA_NO_ADAPT);
+	}
+
 	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_PWRMODEUSERDATA0),
 			DL_FC0ProtectionTimeOutVal_Default);
 	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_PWRMODEUSERDATA1),
@@ -8447,7 +8458,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	if ((hba->ufs_version != UFSHCI_VERSION_10) &&
 	    (hba->ufs_version != UFSHCI_VERSION_11) &&
 	    (hba->ufs_version != UFSHCI_VERSION_20) &&
-	    (hba->ufs_version != UFSHCI_VERSION_21))
+	    (hba->ufs_version != UFSHCI_VERSION_21) &&
+	    (hba->ufs_version != UFSHCI_VERSION_30))
 		dev_err(hba->dev, "invalid UFS version 0x%x\n",
 			hba->ufs_version);
 
diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h
index c2961d3..f2ee816 100644
--- a/drivers/scsi/ufs/ufshci.h
+++ b/drivers/scsi/ufs/ufshci.h
@@ -104,6 +104,7 @@ enum {
 	UFSHCI_VERSION_11 = 0x00010100, /* 1.1 */
 	UFSHCI_VERSION_20 = 0x00000200, /* 2.0 */
 	UFSHCI_VERSION_21 = 0x00000210, /* 2.1 */
+	UFSHCI_VERSION_30 = 0x00000300, /* 3.0 */
 };
 
 /*
diff --git a/drivers/scsi/ufs/unipro.h b/drivers/scsi/ufs/unipro.h
index 3dc4d8b..5a724b2 100644
--- a/drivers/scsi/ufs/unipro.h
+++ b/drivers/scsi/ufs/unipro.h
@@ -146,6 +146,12 @@
 #define PA_SLEEPNOCONFIGTIME	0x15A2
 #define PA_STALLNOCONFIGTIME	0x15A3
 #define PA_SAVECONFIGTIME	0x15A4
+#define PA_TXHSADAPTTYPE	0x15D4
+
+/* Adpat type for PA_TXHSADAPTTYPE attribute */
+#define PA_REFRESH_ADAPT	0x00
+#define PA_INITIAL_ADAPT	0x01
+#define PA_NO_ADAPT		0x03
 
 #define PA_TACTIVATE_TIME_UNIT_US	10
 #define PA_HIBERN8_TIME_UNIT_US		100
@@ -203,6 +209,7 @@ enum ufs_hs_gear_tag {
 	UFS_HS_G1,		/* HS Gear 1 (default for reset) */
 	UFS_HS_G2,		/* HS Gear 2 */
 	UFS_HS_G3,		/* HS Gear 3 */
+	UFS_HS_G4,		/* HS Gear 4 */
 };
 
 enum ufs_unipro_ver {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project