[PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

[PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

[Can Guo]

From: Subhash Jadavani <subhashj@codeaurora.org>

This change introduces a func ufshcd_set_clk_freq() to explicitly
set clock frequency so that it can be used in reset_and_resotre path and
in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock scaling
error out path.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2a2a63b..63aaa88f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -855,28 +855,29 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
 		return false;
 }
 
-static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+/**
+ * ufshcd_set_clk_freq - set UFS controller clock frequencies
+ * @hba: per adapter instance
+ * @scale_up: If True, set max possible frequency othewise set low frequency
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
 {
 	int ret = 0;
 	struct ufs_clk_info *clki;
 	struct list_head *head = &hba->clk_list_head;
-	ktime_t start = ktime_get();
-	bool clk_state_changed = false;
 
 	if (list_empty(head))
 		goto out;
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
-	if (ret)
-		return ret;
-
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
 			if (scale_up && clki->max_freq) {
 				if (clki->curr_freq == clki->max_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->max_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				if (clki->curr_freq == clki->min_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->min_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				clki->name, clk_get_rate(clki->clk));
 	}
 
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_scale_clks - scale up or scale down UFS controller clocks
+ * @hba: per adapter instance
+ * @scale_up: True if scaling up and false if scaling down
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+{
+	int ret = 0;
+
+	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
+	if (ret)
+		return ret;
+
+	ret = ufshcd_set_clk_freq(hba, scale_up);
+	if (ret)
+		return ret;
+
 	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	if (ret) {
+		ufshcd_set_clk_freq(hba, !scale_up);
+		return ret;
+	}
 
-out:
-	if (clk_state_changed)
-		trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
-			(scale_up ? "up" : "down"),
-			ktime_to_us(ktime_sub(ktime_get(), start)), ret);
 	return ret;
 }
 
@@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 
 	ret = ufshcd_clock_scaling_prepare(hba);
 	if (ret)
-		return ret;
+		goto out;
 
 	/* scale down the gear before scaling down clocks */
 	if (!scale_up) {
 		ret = ufshcd_scale_gear(hba, false);
 		if (ret)
-			goto out;
+			goto clk_scaling_unprepare;
 	}
 
 	ret = ufshcd_scale_clks(hba, scale_up);
-	if (ret) {
-		if (!scale_up)
-			ufshcd_scale_gear(hba, true);
-		goto out;
-	}
+	if (ret)
+		goto scale_up_gear;
 
 	/* scale up the gear after scaling up clocks */
 	if (scale_up) {
 		ret = ufshcd_scale_gear(hba, true);
 		if (ret) {
 			ufshcd_scale_clks(hba, false);
-			goto out;
+			goto clk_scaling_unprepare;
 		}
 	}
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	goto clk_scaling_unprepare;
 
-out:
+scale_up_gear:
+	if (!scale_up)
+		ufshcd_scale_gear(hba, true);
+clk_scaling_unprepare:
 	ufshcd_clock_scaling_unprepare(hba);
+out:
 	ufshcd_release(hba);
 	return ret;
 }
@@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	/* scale up clocks to max frequency before full reinitialization */
-	ufshcd_scale_clks(hba, true);
+	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
 	if (err)
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH 2/2] scsi: ufs: Do not rely on prefetched data

[Can Guo]

We were setting bActiveICCLevel attribute for UFS device only once but
type of this attribute has changed from persistent to volatile since UFS
device specification v2.1. This attribute is set to the default value after
power cycle or hardware reset event. It isn't safe to rely on prefetched
data (only used for bActiveICCLevel attribute now). Hence this change
removes the code related to data prefetching and set this parameter on
every attempt to probe the UFS device.

Signed-off-by: Can Guo <cang@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 63aaa88f..99c7fca 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6458,11 +6458,12 @@ static u32 ufshcd_find_max_sup_active_icc_level(struct ufs_hba *hba,
 	return icc_level;
 }
 
-static void ufshcd_init_icc_levels(struct ufs_hba *hba)
+static void ufshcd_set_active_icc_lvl(struct ufs_hba *hba)
 {
 	int ret;
 	int buff_len = hba->desc_size.pwr_desc;
 	u8 *desc_buf;
+	u32 icc_level;
 
 	desc_buf = kmalloc(buff_len, GFP_KERNEL);
 	if (!desc_buf)
@@ -6477,20 +6478,17 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba)
 		goto out;
 	}
 
-	hba->init_prefetch_data.icc_level =
-			ufshcd_find_max_sup_active_icc_level(hba,
-			desc_buf, buff_len);
-	dev_dbg(hba->dev, "%s: setting icc_level 0x%x",
-			__func__, hba->init_prefetch_data.icc_level);
+	icc_level = ufshcd_find_max_sup_active_icc_level(hba, desc_buf,
+							 buff_len);
+	dev_dbg(hba->dev, "%s: setting icc_level 0x%x", __func__, icc_level);
 
 	ret = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
-		QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0,
-		&hba->init_prefetch_data.icc_level);
+		QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0, &icc_level);
 
 	if (ret)
 		dev_err(hba->dev,
 			"%s: Failed configuring bActiveICCLevel = %d ret = %d",
-			__func__, hba->init_prefetch_data.icc_level , ret);
+			__func__, icc_level, ret);
 
 out:
 	kfree(desc_buf);
@@ -6996,8 +6994,6 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 {
 	int ret;
 
-	ufshcd_init_icc_levels(hba);
-
 	/* Add required well known logical units to scsi mid layer */
 	ret = ufshcd_scsi_add_wlus(hba);
 	if (ret)
@@ -7095,6 +7091,14 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 		}
 	}
 
+	/*
+	 * bActiveICCLevel is volatile for UFS device (as per latest v2.1 spec)
+	 * and for removable UFS card as well, hence always set the parameter.
+	 * Note: Error handler may issue the device reset hence resetting
+	 *       bActiveICCLevel as well so it is always safe to set this here.
+	 */
+	ufshcd_set_active_icc_lvl(hba);
+
 	/* set the state as operational after switching to desired gear */
 	hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
 
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index d45a044..5652d39 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -404,15 +404,6 @@ struct ufs_clk_scaling {
 	bool is_suspended;
 };
 
-/**
- * struct ufs_init_prefetch - contains data that is pre-fetched once during
- * initialization
- * @icc_level: icc level which was read during initialization
- */
-struct ufs_init_prefetch {
-	u32 icc_level;
-};
-
 #define UFS_ERR_REG_HIST_LENGTH 8
 /**
  * struct ufs_err_reg_hist - keeps history of errors
@@ -544,7 +535,6 @@ enum ufshcd_quirks {
  * @intr_mask: Interrupt Mask Bits
  * @ee_ctrl_mask: Exception event control mask
  * @is_powered: flag to check if HBA is powered
- * @init_prefetch_data: data pre-fetched during initialization
  * @eh_work: Worker to handle UFS errors that require s/w attention
  * @eeh_work: Worker to handle exception events
  * @errors: HBA errors
@@ -632,7 +622,6 @@ struct ufs_hba {
 	u32 intr_mask;
 	u16 ee_ctrl_mask;
 	bool is_powered;
-	struct ufs_init_prefetch init_prefetch_data;
 
 	/* Work Queues */
 	struct work_struct eh_work;
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

[Can Guo]

From: Subhash Jadavani <subhashj@codeaurora.org>

This change introduces a func ufshcd_set_clk_freq() to explicitly
set clock frequency so that it can be used in reset_and_resotre path and
in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock scaling
error out path.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2a2a63b..63aaa88f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -855,28 +855,29 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
 		return false;
 }
 
-static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+/**
+ * ufshcd_set_clk_freq - set UFS controller clock frequencies
+ * @hba: per adapter instance
+ * @scale_up: If True, set max possible frequency othewise set low frequency
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
 {
 	int ret = 0;
 	struct ufs_clk_info *clki;
 	struct list_head *head = &hba->clk_list_head;
-	ktime_t start = ktime_get();
-	bool clk_state_changed = false;
 
 	if (list_empty(head))
 		goto out;
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
-	if (ret)
-		return ret;
-
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
 			if (scale_up && clki->max_freq) {
 				if (clki->curr_freq == clki->max_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->max_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				if (clki->curr_freq == clki->min_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->min_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				clki->name, clk_get_rate(clki->clk));
 	}
 
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_scale_clks - scale up or scale down UFS controller clocks
+ * @hba: per adapter instance
+ * @scale_up: True if scaling up and false if scaling down
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+{
+	int ret = 0;
+
+	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
+	if (ret)
+		return ret;
+
+	ret = ufshcd_set_clk_freq(hba, scale_up);
+	if (ret)
+		return ret;
+
 	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	if (ret) {
+		ufshcd_set_clk_freq(hba, !scale_up);
+		return ret;
+	}
 
-out:
-	if (clk_state_changed)
-		trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
-			(scale_up ? "up" : "down"),
-			ktime_to_us(ktime_sub(ktime_get(), start)), ret);
 	return ret;
 }
 
@@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 
 	ret = ufshcd_clock_scaling_prepare(hba);
 	if (ret)
-		return ret;
+		goto out;
 
 	/* scale down the gear before scaling down clocks */
 	if (!scale_up) {
 		ret = ufshcd_scale_gear(hba, false);
 		if (ret)
-			goto out;
+			goto clk_scaling_unprepare;
 	}
 
 	ret = ufshcd_scale_clks(hba, scale_up);
-	if (ret) {
-		if (!scale_up)
-			ufshcd_scale_gear(hba, true);
-		goto out;
-	}
+	if (ret)
+		goto scale_up_gear;
 
 	/* scale up the gear after scaling up clocks */
 	if (scale_up) {
 		ret = ufshcd_scale_gear(hba, true);
 		if (ret) {
 			ufshcd_scale_clks(hba, false);
-			goto out;
+			goto clk_scaling_unprepare;
 		}
 	}
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	goto clk_scaling_unprepare;
 
-out:
+scale_up_gear:
+	if (!scale_up)
+		ufshcd_scale_gear(hba, true);
+clk_scaling_unprepare:
 	ufshcd_clock_scaling_unprepare(hba);
+out:
 	ufshcd_release(hba);
 	return ret;
 }
@@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	/* scale up clocks to max frequency before full reinitialization */
-	ufshcd_scale_clks(hba, true);
+	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
 	if (err)
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

RE: [PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

[Avri Altman]

Hi,

> 
> From: Subhash Jadavani <subhashj@codeaurora.org>
> 
> This change introduces a func ufshcd_set_clk_freq() to explicitly
> set clock frequency so that it can be used in reset_and_resotre path and
> in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock scaling
> error out path.
> 
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 2a2a63b..63aaa88f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -855,28 +855,29 @@ static bool
> ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
>                 return false;
>  }
> 
> -static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
> +/**
> + * ufshcd_set_clk_freq - set UFS controller clock frequencies
> + * @hba: per adapter instance
> + * @scale_up: If True, set max possible frequency othewise set low
> frequency
> + *
> + * Returns 0 if successful
> + * Returns < 0 for any other errors
> + */
> +static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
Personally I prefer using the convention of "__scale_clks" to describe the privet core of scale_clks,
But I know that many people are against it.

>  {
>         int ret = 0;
>         struct ufs_clk_info *clki;
>         struct list_head *head = &hba->clk_list_head;
> -       ktime_t start = ktime_get();
> -       bool clk_state_changed = false;
> 
>         if (list_empty(head))
>                 goto out;
> 
> -       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
> -       if (ret)
> -               return ret;
> -
>         list_for_each_entry(clki, head, list) {
>                 if (!IS_ERR_OR_NULL(clki->clk)) {
>                         if (scale_up && clki->max_freq) {
>                                 if (clki->curr_freq == clki->max_freq)
>                                         continue;
> 
> -                               clk_state_changed = true;
>                                 ret = clk_set_rate(clki->clk, clki->max_freq);
>                                 if (ret) {
>                                         dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed,
> %d\n",
> @@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba,
> bool scale_up)
>                                 if (clki->curr_freq == clki->min_freq)
>                                         continue;
> 
> -                               clk_state_changed = true;
>                                 ret = clk_set_rate(clki->clk, clki->min_freq);
>                                 if (ret) {
>                                         dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed,
> %d\n",
> @@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba *hba,
> bool scale_up)
>                                 clki->name, clk_get_rate(clki->clk));
>         }
> 
> +out:
> +       return ret;
> +}
> +
> +/**
> + * ufshcd_scale_clks - scale up or scale down UFS controller clocks
> + * @hba: per adapter instance
> + * @scale_up: True if scaling up and false if scaling down
> + *
> + * Returns 0 if successful
> + * Returns < 0 for any other errors
> + */
> +static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
> +{
> +       int ret = 0;
> +
> +       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
> +       if (ret)
> +               return ret;
> +
> +       ret = ufshcd_set_clk_freq(hba, scale_up);
> +       if (ret)
> +               return ret;
> +
>         ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
> +       if (ret) {
> +               ufshcd_set_clk_freq(hba, !scale_up);
> +               return ret;
> +       }
> 
> -out:
> -       if (clk_state_changed)
> -               trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
> -                       (scale_up ? "up" : "down"),
> -                       ktime_to_us(ktime_sub(ktime_get(), start)), ret);

Why remove the ufshcd_profile_clk_scaling trace?


>         return ret;
>  }
> 
> @@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
> 
>         ret = ufshcd_clock_scaling_prepare(hba);
>         if (ret)
> -               return ret;
> +               goto out;
Are you fixing here a hold without release?
Should make note of that.

> 
>         /* scale down the gear before scaling down clocks */
>         if (!scale_up) {
>                 ret = ufshcd_scale_gear(hba, false);
>                 if (ret)
> -                       goto out;
> +                       goto clk_scaling_unprepare;
>         }
> 
>         ret = ufshcd_scale_clks(hba, scale_up);
> -       if (ret) {
> -               if (!scale_up)
> -                       ufshcd_scale_gear(hba, true);
> -               goto out;
> -       }
> +       if (ret)
> +               goto scale_up_gear;
> 
>         /* scale up the gear after scaling up clocks */
>         if (scale_up) {
>                 ret = ufshcd_scale_gear(hba, true);
>                 if (ret) {
>                         ufshcd_scale_clks(hba, false);
> -                       goto out;
> +                       goto clk_scaling_unprepare;
>                 }
>         }
> 
> -       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
> +       goto clk_scaling_unprepare;
I think you should find a way to make this function more readable.
Adding all those "spaghetti" gotos making it even harder to read. 

Thanks,
Avri

> 
> -out:
> +scale_up_gear:
> +       if (!scale_up)
> +               ufshcd_scale_gear(hba, true);
> +clk_scaling_unprepare:
>         ufshcd_clock_scaling_unprepare(hba);
> +out:
>         ufshcd_release(hba);
>         return ret;
>  }
> @@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct
> ufs_hba *hba)
>         spin_unlock_irqrestore(hba->host->host_lock, flags);
> 
>         /* scale up clocks to max frequency before full reinitialization */
> -       ufshcd_scale_clks(hba, true);
> +       ufshcd_set_clk_freq(hba, true);
> 
>         err = ufshcd_hba_enable(hba);
>         if (err)
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
> Linux Foundation Collaborative Project.

Re: [PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

[Can Guo]

On 2020-03-18 16:19, Avri Altman wrote:
> Hi,
> 
>> 
>> From: Subhash Jadavani <subhashj@codeaurora.org>
>> 
>> This change introduces a func ufshcd_set_clk_freq() to explicitly
>> set clock frequency so that it can be used in reset_and_resotre path 
>> and
>> in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock 
>> scaling
>> error out path.
>> 
>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> 
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 2a2a63b..63aaa88f 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -855,28 +855,29 @@ static bool
>> ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
>>                 return false;
>>  }
>> 
>> -static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
>> +/**
>> + * ufshcd_set_clk_freq - set UFS controller clock frequencies
>> + * @hba: per adapter instance
>> + * @scale_up: If True, set max possible frequency othewise set low
>> frequency
>> + *
>> + * Returns 0 if successful
>> + * Returns < 0 for any other errors
>> + */
>> +static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
> Personally I prefer using the convention of "__scale_clks" to describe
> the privet core of scale_clks,
> But I know that many people are against it.
> 
>>  {
>>         int ret = 0;
>>         struct ufs_clk_info *clki;
>>         struct list_head *head = &hba->clk_list_head;
>> -       ktime_t start = ktime_get();
>> -       bool clk_state_changed = false;
>> 
>>         if (list_empty(head))
>>                 goto out;
>> 
>> -       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
>> -       if (ret)
>> -               return ret;
>> -
>>         list_for_each_entry(clki, head, list) {
>>                 if (!IS_ERR_OR_NULL(clki->clk)) {
>>                         if (scale_up && clki->max_freq) {
>>                                 if (clki->curr_freq == clki->max_freq)
>>                                         continue;
>> 
>> -                               clk_state_changed = true;
>>                                 ret = clk_set_rate(clki->clk, 
>> clki->max_freq);
>>                                 if (ret) {
>>                                         dev_err(hba->dev, "%s: %s clk 
>> set rate(%dHz) failed,
>> %d\n",
>> @@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba,
>> bool scale_up)
>>                                 if (clki->curr_freq == clki->min_freq)
>>                                         continue;
>> 
>> -                               clk_state_changed = true;
>>                                 ret = clk_set_rate(clki->clk, 
>> clki->min_freq);
>>                                 if (ret) {
>>                                         dev_err(hba->dev, "%s: %s clk 
>> set rate(%dHz) failed,
>> %d\n",
>> @@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba 
>> *hba,
>> bool scale_up)
>>                                 clki->name, clk_get_rate(clki->clk));
>>         }
>> 
>> +out:
>> +       return ret;
>> +}
>> +
>> +/**
>> + * ufshcd_scale_clks - scale up or scale down UFS controller clocks
>> + * @hba: per adapter instance
>> + * @scale_up: True if scaling up and false if scaling down
>> + *
>> + * Returns 0 if successful
>> + * Returns < 0 for any other errors
>> + */
>> +static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
>> +{
>> +       int ret = 0;
>> +
>> +       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
>> +       if (ret)
>> +               return ret;
>> +
>> +       ret = ufshcd_set_clk_freq(hba, scale_up);
>> +       if (ret)
>> +               return ret;
>> +
>>         ret = ufshcd_vops_clk_scale_notify(hba, scale_up, 
>> POST_CHANGE);
>> +       if (ret) {
>> +               ufshcd_set_clk_freq(hba, !scale_up);
>> +               return ret;
>> +       }
>> 
>> -out:
>> -       if (clk_state_changed)
>> -               trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
>> -                       (scale_up ? "up" : "down"),
>> -                       ktime_to_us(ktime_sub(ktime_get(), start)), 
>> ret);
> 
> Why remove the ufshcd_profile_clk_scaling trace?
> 
> 

Shall add it back, this is just a collection of Subhash's changes.

>>         return ret;
>>  }
>> 
>> @@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba
>> *hba, bool scale_up)
>> 
>>         ret = ufshcd_clock_scaling_prepare(hba);
>>         if (ret)
>> -               return ret;
>> +               goto out;
> Are you fixing here a hold without release?
> Should make note of that.
> 

Yes, true

>> 
>>         /* scale down the gear before scaling down clocks */
>>         if (!scale_up) {
>>                 ret = ufshcd_scale_gear(hba, false);
>>                 if (ret)
>> -                       goto out;
>> +                       goto clk_scaling_unprepare;
>>         }
>> 
>>         ret = ufshcd_scale_clks(hba, scale_up);
>> -       if (ret) {
>> -               if (!scale_up)
>> -                       ufshcd_scale_gear(hba, true);
>> -               goto out;
>> -       }
>> +       if (ret)
>> +               goto scale_up_gear;
>> 
>>         /* scale up the gear after scaling up clocks */
>>         if (scale_up) {
>>                 ret = ufshcd_scale_gear(hba, true);
>>                 if (ret) {
>>                         ufshcd_scale_clks(hba, false);
>> -                       goto out;
>> +                       goto clk_scaling_unprepare;
>>                 }
>>         }
>> 
>> -       ret = ufshcd_vops_clk_scale_notify(hba, scale_up, 
>> POST_CHANGE);
>> +       goto clk_scaling_unprepare;
> I think you should find a way to make this function more readable.
> Adding all those "spaghetti" gotos making it even harder to read.
> 
> Thanks,
> Avri
> 

This is just a collection of Subhash's changes. I think the 2
clk_scaling_unprepare and out gotos make sense, but the
scale_up_gear goto is a bit vague. I will remove the
scale_up_gear goto.

Thanks,

Can Guo.

>> 
>> -out:
>> +scale_up_gear:
>> +       if (!scale_up)
>> +               ufshcd_scale_gear(hba, true);
>> +clk_scaling_unprepare:
>>         ufshcd_clock_scaling_unprepare(hba);
>> +out:
>>         ufshcd_release(hba);
>>         return ret;
>>  }
>> @@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct
>> ufs_hba *hba)
>>         spin_unlock_irqrestore(hba->host->host_lock, flags);
>> 
>>         /* scale up clocks to max frequency before full 
>> reinitialization */
>> -       ufshcd_scale_clks(hba, true);
>> +       ufshcd_set_clk_freq(hba, true);
>> 
>>         err = ufshcd_hba_enable(hba);
>>         if (err)
>> --
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
>> Linux Foundation Collaborative Project.