[PATCH v1 1/2] scsi: ufs: core: Remove UFS_DEVICE_QUIRK_DELAY_AFTER_LPM quirk
Peter Wang (王信友)
peter.wang at mediatek.com
Thu Oct 2 20:10:01 PDT 2025
On Thu, 2025-10-02 at 11:48 -0700, Bao D. Nguyen wrote:
>
>
> Hi Peter,
>
> The current Mediatek platform driver applies this quirk to all ufs
> vendors which is consistent with what we would like to do in the
> Qualcomm platform driver per the vendor's requests.
>
> I do see that, about 5 years ago, Mediatek merged a patch to keep the
> device vcc always on, probably to workaround some HW issues. Since
Hi Bao,
Yes, some UFS devices may have issues when turning off VCC.
> this
> is a very old patch and the impact of this change on a broken
> hardware
> is minimal, I would like weight the benefit of cleaning up the ufs
> core
> driver by removing the unnecessary quirk
> UFS_DEVICE_QUIRK_DELAY_AFTER_LPM vs the inconvenience of a 5ms
> (potentially reduce to 2ms) delay impact it may cause on an old
> broken
> HW in the suspend/shutdown path.
>
> I believe removing the UFS_DEVICE_QUIRK_DELAY_AFTER_LPM quirk in the
> ufs
> core driver as well as all the platform drivers yields positive net
> benefits in this case.
>
> Thanks, Bao
>
>
I think you misunderstood my point.
I am okay with removing this flag, but this patch will cause
devices with VCC always on to unnecessarily wait for the
delay, resulting in wasted time.
Thanks
Peter
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