Re: [PATCH v1] ufs: core: Remove unnecessary block I/O quiesce for clock scaling

On Wed, Jul 22, 2026 at 10:25:32AM +0800, Shawn Guo wrote:
> On Tue, Jul 21, 2026 at 12:54:01PM +0000, Peter Wang (王信友) wrote:
> > On Tue, 2026-07-21 at 14:58 +0800, Shawn Guo wrote:
> > > A revert of commit 85b2b9662854 ("scsi: ufs: core: Remove unnecessary
> > > block I/O quiesce for clock scaling") fixes the regression for me.
> > > 
> > > Shawn
> > 
> > Hi Shawn,
> 
> Hi Peter,
> 
> > What is the probability of this issue occurring?
> 
> It seems 100% per my testing.
>

Whenever clk scaling gets triggered. So this affects all Qcom UFS platforms.
 
> > Is this a design limitation of the Qualcomm platform or?
> 

Qcom Host Controllers doesn't support scaling clocks when the traffic is
ongoing. So this patch certainly cannot work on our platforms.

If you want to pursue, you should limit this change to MediaTek platforms. But
nevertheless, this patch should be reverted as it breaks UFS on all Qcom
platforms.

- Mani

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