Re: [PATCH v1] scsi: ufs: core: Remove the ufshcd_release in ufshcd_err_handling_prepare

[Can Guo]

On 2/1/2024 1:44 AM, Bart Van Assche wrote:
> On 1/22/24 00:33, SEO HOYOUNG wrote:
> > This is because ufshcd_errhandling_prepare() and
> > ufshcd_err_handling_unprepare() repeatedly release calls.
>
> It would have been much more clear if it would have been mentioned that
> ufshcd_err_handling_prepare() should call ufshcd_hold() once and
> also that ufshcd_err_handling_unprepare() should call ufshcd_release()
> once.
>
> Additionally, a Fixes: tag is missing. Is this patch perhaps a fix for 
> commit
> c72e79c0ad2b ("scsi: ufs: Recover HBA runtime PM error in error handler")?
> Can Guo, since you wrote that patch, can you please take a look at this 
> patch?
>
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > index 7c59d7a02243..423e83074a20 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -6351,7 +6351,6 @@ static void ufshcd_err_handling_prepare(struct 
> > ufs_hba *hba)
> >           ufshcd_hold(hba);
> >           if (!ufshcd_is_clkgating_allowed(hba))
> >               ufshcd_setup_clocks(hba, true);
> > -        ufshcd_release(hba);

When we are here, it means runtime resume has failed.

When I wrote the code (in older kernel), ufshcd_runtime_resume(), if 
fails, bails without calling ufshcd_release(), eventually 
ufshcd_err_handling_unprepare() would call ufshcd_release() to balance.

But now, I see that if __ufshcd_wl_resume() fails, ufshcd_release() is 
called anyways, so ufshcd_release() is not required here. Hence,

Reviewed-by: Can Guo <quic_cang@xxxxxxxxxxx>

> >           pm_op = hba->is_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
> >           ufshcd_vops_resume(hba, pm_op);
> >       } else {
>
> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>