Re: [PATCH 5/7] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

[Can Guo]

On 2020-02-09 15:48, Avri Altman wrote:
> You didn't address any of my comments to this patch.
>
> Thanks,
> Avri

Replied in that thread.

Thanks,
Can Guo.

> > The async version of ufshcd_hold(async == true), which is only called
> > in queuecommand path as for now, is expected to work in atomic 
> > context,
> > thus it should not sleep or schedule out. When it runs into the 
> > condition
> > that clocks are ON but link is still in hibern8 state, it should bail 
> > out
> > without flushing the clock ungate work.
> >
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> > Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
> > Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> > Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
> > Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index bbc2607..e8f7f9d 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -1518,6 +1518,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool 
> > async)
> >                  */
> >                 if (ufshcd_can_hibern8_during_gating(hba) &&
> >                     ufshcd_is_link_hibern8(hba)) {
> > +                       if (async) {
> > +                               rc = -EAGAIN;
> > +                               hba->clk_gating.active_reqs--;
> > +                               break;
> > +                       }
> >                         spin_unlock_irqrestore(hba->host->host_lock, 
> > flags);
> >                         flush_work(&hba->clk_gating.ungate_work);
> >                         spin_lock_irqsave(hba->host->host_lock, 
> > flags);
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> > Forum,
> > a Linux Foundation Collaborative Project