scsi: ufs: core: Fix clk scaling to be conditional in reset and restore

[PATCH v2] scsi: ufs: core: Fix clk scaling to be conditional in reset and restore

Posted by Anvith Dosapati 7 months, 3 weeks ago

From: anvithdosapati <anvithdosapati@google.com>

In ufshcd_host_reset_and_restore, scale up clocks only when clock
scaling is supported. Without this change cpu latency is voted for 0
(ufshcd_pm_qos_update) during resume unconditionally.

Signed-off-by: anvithdosapati <anvithdosapati@google.com>
Fixes: a3cd5ec55f6c7 ("scsi: ufs: add load based scaling of UFS gear")
Cc: stable@vger.kernel.org
---
v2:
- Update commit message
- Add Fixes and Cc stable

 drivers/ufs/core/ufshcd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 4410e7d93b7d..fac381ea2b3a 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -7802,7 +7802,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	hba->silence_err_logs = false;
 
 	/* scale up clocks to max frequency before full reinitialization */
-	ufshcd_scale_clks(hba, ULONG_MAX, true);
+	if (ufshcd_is_clkscaling_supported(hba))
+		ufshcd_scale_clks(hba, ULONG_MAX, true);
 
 	err = ufshcd_hba_enable(hba);
 
-- 
2.50.0.rc1.591.g9c95f17f64-goog

Re: [PATCH v2] scsi: ufs: core: Fix clk scaling to be conditional in reset and restore

Posted by Bart Van Assche 7 months, 3 weeks ago

On 6/16/25 1:57 AM, Anvith Dosapati wrote:
> From: anvithdosapati <anvithdosapati@google.com>
> 
> In ufshcd_host_reset_and_restore, scale up clocks only when clock
> scaling is supported. Without this change cpu latency is voted for 0
> (ufshcd_pm_qos_update) during resume unconditionally.
> 
> Signed-off-by: anvithdosapati <anvithdosapati@google.com>
> Fixes: a3cd5ec55f6c7 ("scsi: ufs: add load based scaling of UFS gear")
> Cc: stable@vger.kernel.org
> ---
> v2:
> - Update commit message
> - Add Fixes and Cc stable
> 
>   drivers/ufs/core/ufshcd.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 4410e7d93b7d..fac381ea2b3a 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -7802,7 +7802,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
>   	hba->silence_err_logs = false;
>   
>   	/* scale up clocks to max frequency before full reinitialization */
> -	ufshcd_scale_clks(hba, ULONG_MAX, true);
> +	if (ufshcd_is_clkscaling_supported(hba))
> +		ufshcd_scale_clks(hba, ULONG_MAX, true);
>   
>   	err = ufshcd_hba_enable(hba);
>   

Reviewed-by: Bart Van Assche <bvanassche@acm.org>