[PATCH v2 0/2] ufs: allow host driver disable wb toggle druing clock scaling

[PATCH v2 0/2] ufs: allow host driver disable wb toggle druing clock scaling

[peter.wang]

From: Peter Wang <peter.wang@mediatek.com>

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

Peter Wang (2):
  ufs: core: introduce a choice of wb toggle during clock scaling
  ufs: host: support wb toggle with clock scaling

 drivers/ufs/core/ufs-sysfs.c | 3 ++-
 drivers/ufs/core/ufshcd.c    | 8 +++++---
 drivers/ufs/host/ufs-qcom.c  | 2 +-
 include/ufs/ufshcd.h         | 7 +++++++
 4 files changed, 15 insertions(+), 5 deletions(-)

-- 
2.18.0

[PATCH v2 1/2] ufs: core: introduce a choice of wb toggle during clock scaling

[peter.wang]

From: Peter Wang <peter.wang@mediatek.com>

host driver may wan't disable/enable write booster during clock scaling.
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.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
---
 drivers/ufs/core/ufs-sysfs.c | 3 ++-
 drivers/ufs/core/ufshcd.c    | 8 +++++---
 include/ufs/ufshcd.h         | 7 +++++++
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 0a088b47d557..8fa1679ffd1a 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -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_can_wb_during_scaling(hba))) {
 		/*
 		 * If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB
 		 * on/off will be done while clock scaling up/down.
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 3d367be71728..d86826e958e6 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -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_can_wb_during_scaling(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);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index a92271421718..4bd35d68acde 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -648,6 +648,9 @@ enum ufshcd_caps {
 	 * notification if it is supported by the UFS device.
 	 */
 	UFSHCD_CAP_TEMP_NOTIF				= 1 << 11,
+
+	/* Allow WB with clk scaling */
+	UFSHCD_CAP_WB_WITH_CLK_SCALING			= 1 << 12,
 };
 
 struct ufs_hba_variant_params {
@@ -1004,6 +1007,10 @@ static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba)
 {
 	return hba->caps & UFSHCD_CAP_WB_EN;
 }
+static inline bool ufshcd_can_wb_during_scaling(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))
-- 
2.18.0

[PATCH v2 2/2] ufs: host: support wb toggle with clock scaling

[peter.wang]

From: Peter Wang <peter.wang@mediatek.com>

Set UFSHCD_CAP_WB_WITH_CLK_SCALING for qcom to compatible legacy design.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
---
 drivers/ufs/host/ufs-qcom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index f10d4668814c..f8c9a78e7776 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -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;
-- 
2.18.0

Re: [PATCH v2 0/2] ufs: allow host driver disable wb toggle druing clock scaling

[Stanley Chu]

Hi Peter,

On Tue, Aug 2, 2022 at 9:25 PM <peter.wang@mediatek.com> wrote:
>
> From: Peter Wang <peter.wang@mediatek.com>
>
> Mediatek ufs do not want to toggle write booster during clock scaling.
> This patch set allow host driver disable wb toggle during clock scaling.
>
> Peter Wang (2):
>   ufs: core: introduce a choice of wb toggle during clock scaling
>   ufs: host: support wb toggle with clock scaling
>
>  drivers/ufs/core/ufs-sysfs.c | 3 ++-
>  drivers/ufs/core/ufshcd.c    | 8 +++++---
>  drivers/ufs/host/ufs-qcom.c  | 2 +-
>  include/ufs/ufshcd.h         | 7 +++++++
>  4 files changed, 15 insertions(+), 5 deletions(-)
>
> --
> 2.18.0
>
Except for some typos in the commit messages, otherwise this series
looks good to me.

Please feel free to add
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>