ufs: allow host driver disable wb toggle druing clock scaling

PATCH Superseded [email protected] 2 participants 3 messages Aug 3, 2022 – Aug 4, 2022

Subsystems (5)

SCSI Arm Qualcomm mailing list Arm MediaTek UFS host controller +1 more subsystems

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[email protected]

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2022-08-03 03:03 UTC #0 lore raw

PATCH v4 1/1 ufs: allow host driver disable wb toggle druing clock scaling

From: Peter Wang <[email protected]>

Mediatek ufs do not want to toggle write booster during clock scaling. This patch allow host driver disable wb toggle during clock scaling.

So, introduce a flag UFSHCD_CAP_WB_WITH_CLK_SCALING to decouple WB and clock scaling. UFSHCD_CAP_WB_WITH_CLK_SCALING only valid when UFSHCD_CAP_CLK_SCALING is set. Just like UFSHCD_CAP_HIBERN8_WITH_CLK_GATING is valid only when UFSHCD_CAP_CLK_GATING set.

Set UFSHCD_CAP_WB_WITH_CLK_SCALING for qcom to compatible legacy design in the same time.

Signed-off-by Peter Wang <[email protected]>

Reviewed-by Stanley Chu <[email protected]>

---
 drivers/ufs/core/ufs-sysfs.c |  3 ++-
 drivers/ufs/core/ufshcd.c    |  8 +++++---
 drivers/ufs/host/ufs-qcom.c  |  2 +-
 include/ufs/ufshcd.h         | 10 ++++++++++
 4 files changed, 18 insertions(+), 5 deletions(-)

drivers/ufs/core/ufs-sysfs.c +2 -1

index 0a088b47d557..7f41f2a69b04 100644
@@ -225,7 +225,8 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
 	unsigned int wb_enable;
 	ssize_t res;
 
-	if (!ufshcd_is_wb_allowed(hba) || ufshcd_is_clkscaling_supported(hba)) {
+	if (!ufshcd_is_wb_allowed(hba) || (ufshcd_is_clkscaling_supported(hba)
+		&& ufshcd_enable_wb_if_scaling_up(hba))) {
 		/*
 		 * If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB
 		 * on/off will be done while clock scaling up/down.

drivers/ufs/core/ufshcd.c +5 -3

index c7b337480e3e..ac50fbe8aeb8 100644
@@ -1301,9 +1301,11 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 	}
 
 	/* Enable Write Booster if we have scaled up else disable it */
-	downgrade_write(&hba->clk_scaling_lock);
-	is_writelock = false;
-	ufshcd_wb_toggle(hba, scale_up);
+	if (ufshcd_enable_wb_if_scaling_up(hba)) {
+		downgrade_write(&hba->clk_scaling_lock);
+		is_writelock = false;
+		ufshcd_wb_toggle(hba, scale_up);
+	}
 
 out_unprepare:
 	ufshcd_clock_scaling_unprepare(hba, is_writelock);

drivers/ufs/host/ufs-qcom.c +1 -1

index f10d4668814c..f8c9a78e7776 100644
@@ -869,7 +869,7 @@ static void ufs_qcom_set_caps(struct ufs_hba *hba)
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 
 	hba->caps |= UFSHCD_CAP_CLK_GATING | UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
-	hba->caps |= UFSHCD_CAP_CLK_SCALING;
+	hba->caps |= UFSHCD_CAP_CLK_SCALING | UFSHCD_CAP_WB_WITH_CLK_SCALING;
 	hba->caps |= UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
 	hba->caps |= UFSHCD_CAP_WB_EN;
 	hba->caps |= UFSHCD_CAP_CRYPTO;

include/ufs/ufshcd.h +10 -0

index a92271421718..5a8fabb9f008 100644
@@ -648,6 +648,12 @@ enum ufshcd_caps {
 	 * notification if it is supported by the UFS device.
 	 */
 	UFSHCD_CAP_TEMP_NOTIF				= 1 << 11,
+
+	/*
+	 * Enable WriteBooster when scaling up the clock and disable
+	 * WriteBooster when scaling the clock down.
+	 */
+	UFSHCD_CAP_WB_WITH_CLK_SCALING			= 1 << 12,
 };
 
 struct ufs_hba_variant_params {

@@ -1004,6 +1010,10 @@ static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba)
 {
 	return hba->caps & UFSHCD_CAP_WB_EN;
 }
+static inline bool ufshcd_enable_wb_if_scaling_up(struct ufs_hba *hba)
+{
+	return hba->caps & UFSHCD_CAP_WB_WITH_CLK_SCALING;
+}
 
 #define ufshcd_writel(hba, val, reg)	\
 	writel((val), (hba)->mmio_base + (reg))

Signature · 1 line

2.18.0

Bart Van Assche

reviewer

2022-08-03 19:29 UTC #1 lore raw

Quoted 1 line · On 8/2/22 20:03, [email protected] wrote:

disable -> to disable?

toggle -> toggling?

druing -> during?

drivers/ufs/core/ufs-sysfs.c static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr, · line 229

Quoted 11 lines

drivers/ufs/core/ufs-sysfs.c +2 -1

index 0a088b47d557..7f41f2a69b04 100644
@@ -225,7 +225,8 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
  	unsigned int wb_enable;
  	ssize_t res;
 
-	if (!ufshcd_is_wb_allowed(hba) || ufshcd_is_clkscaling_supported(hba)) {
+	if (!ufshcd_is_wb_allowed(hba) || (ufshcd_is_clkscaling_supported(hba)
+		&& ufshcd_enable_wb_if_scaling_up(hba))) {

The "&&" is misplaced - it should occur at the end of the previous line. Isn't this something that checkpatch complains about?

drivers/ufs/core/ufs-sysfs.c static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,

Quoted 9 lines

drivers/ufs/core/ufs-sysfs.c +5 -3

  	/* Enable Write Booster if we have scaled up else disable it */
-	downgrade_write(&hba->clk_scaling_lock);
-	is_writelock = false;
-	ufshcd_wb_toggle(hba, scale_up);
+	if (ufshcd_enable_wb_if_scaling_up(hba)) {
+		downgrade_write(&hba->clk_scaling_lock);
+		is_writelock = false;
+		ufshcd_wb_toggle(hba, scale_up);
+	}

Since this code is being modified, please move the "/* Enable" comment to where it should occur (just above the ufshcd_wb_toggle() call).

drivers/ufs/core/ufs-sysfs.c static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba) · line 1016

Quoted 8 lines

drivers/ufs/core/ufs-sysfs.c +4 -0

@@ -1004,6 +1010,10 @@ static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba)
  {
  	return hba->caps & UFSHCD_CAP_WB_EN;
  }
+static inline bool ufshcd_enable_wb_if_scaling_up(struct ufs_hba *hba)
+{
+	return hba->caps & UFSHCD_CAP_WB_WITH_CLK_SCALING;
+}

It seems like a blank line is missing above the new function definition?

Otherwise this patch looks good to me.

Thanks,

Bart.

Peter Wang

author

2022-08-04 02:50 UTC #2 lore raw

Quoted 9 lines · Bart Van Assche

Quoted 1 line · On 8/2/22 20:03, [email protected] wrote:
disable -> to disable?
toggle -> toggling?
druing -> during?

Quoted 16 lines

drivers/ufs/core/ufs-sysfs.c static ssize_t wb_on_store(struct device *dev, · line 231
Quoted 12 lines
drivers/ufs/core/ufs-sysfs.c +2 -0
index 0a088b47d557..7f41f2a69b04 100644
@@ -225,7 +225,8 @@ static ssize_t wb_on_store(struct device *dev, 
 struct device_attribute *attr,
       unsigned int wb_enable;
       ssize_t res;
   -    if (!ufshcd_is_wb_allowed(hba) || ufshcd_is_clkscaling_supported(hba)) {
+    if (!ufshcd_is_wb_allowed(hba) || 
 (ufshcd_is_clkscaling_supported(hba)
+        && ufshcd_enable_wb_if_scaling_up(hba))) {
The "&&" is misplaced - it should occur at the end of the previous line. Isn't this something that checkpatch complains about?
Quoted 1 line
drivers/ufs/core/ufs-sysfs.c +0 -0
       /* Enable Write Booster if we have scaled up else disable it

Quoted 23 lines

drivers/ufs/core/ufs-sysfs.c static ssize_t wb_on_store(struct device *dev,
Quoted 8 lines
drivers/ufs/core/ufs-sysfs.c +5 -3
-    downgrade_write(&hba->clk_scaling_lock);
-    is_writelock = false;
-    ufshcd_wb_toggle(hba, scale_up);
+    if (ufshcd_enable_wb_if_scaling_up(hba)) {
+        downgrade_write(&hba->clk_scaling_lock);
+        is_writelock = false;
+        ufshcd_wb_toggle(hba, scale_up);
+    }
Since this code is being modified, please move the "/* Enable" comment to where it should occur (just above the ufshcd_wb_toggle() call).
drivers/ufs/core/ufs-sysfs.c static inline bool ufshcd_is_wb_allowed(struct · line 1017
Quoted 9 lines
drivers/ufs/core/ufs-sysfs.c +4 -0
@@ -1004,6 +1010,10 @@ static inline bool ufshcd_is_wb_allowed(struct 
 ufs_hba *hba)
   {
       return hba->caps & UFSHCD_CAP_WB_EN;
   }
+static inline bool ufshcd_enable_wb_if_scaling_up(struct ufs_hba *hba)
+{
+    return hba->caps & UFSHCD_CAP_WB_WITH_CLK_SCALING;
+}
It seems like a blank line is missing above the new function definition?

Quoted 3 lines

Otherwise this patch looks good to me.
Thanks,

Hi Bart,

Will fix next version.

Thanks

Peter

Quoted 2 lines

Bart.