Re: [PATCH v4 3/7] scsi: ufs: Fix up auto hibern8 enablement

[Can Guo]

On 2019-11-14 17:23, Avri Altman wrote:
> > Fix up possible unclocked register access to auto hibern8 register in 
> > resume path
> > and through sysfs entry. Meanwhile, enable auto hibern8 only after 
> > device is
> > fully initialized in probe path.
> >
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> Acked-by: Avri Altman <avri.altman@xxxxxxx>
>
> > ---
> >  drivers/scsi/ufs/ufs-sysfs.c | 17 +++++++++++------
> >  drivers/scsi/ufs/ufshcd.c    | 12 ++++++------
> >  2 files changed, 17 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/scsi/ufs/ufs-sysfs.c 
> > b/drivers/scsi/ufs/ufs-sysfs.c index
> > 969a36b..6c2f19e 100644
> > --- a/drivers/scsi/ufs/ufs-sysfs.c
> > +++ b/drivers/scsi/ufs/ufs-sysfs.c
> > @@ -126,13 +126,18 @@ static void ufshcd_auto_hibern8_update(struct
> > ufs_hba *hba, u32 ahit)
> >                 return;
> >
> >         spin_lock_irqsave(hba->host->host_lock, flags);
> > -       if (hba->ahit == ahit)
> > -               goto out_unlock;
> > -       hba->ahit = ahit;
> > -       if (!pm_runtime_suspended(hba->dev))
> > -               ufshcd_writel(hba, hba->ahit, 
> > REG_AUTO_HIBERNATE_IDLE_TIMER);
> > -out_unlock:
> > +       if (hba->ahit != ahit)
> > +               hba->ahit = ahit;
> >         spin_unlock_irqrestore(hba->host->host_lock, flags);
> > +       if (!pm_runtime_suspended(hba->dev)) {
> > +               pm_runtime_get_sync(hba->dev);
> > +               ufshcd_hold(hba, false);
> > +               spin_lock_irqsave(hba->host->host_lock, flags);
> > +               ufshcd_writel(hba, hba->ahit, 
> > REG_AUTO_HIBERNATE_IDLE_TIMER);
> > +               spin_unlock_irqrestore(hba->host->host_lock, flags);
> Call ufshcd_auto_hibern8_enable instead of open coding?

In that case, we would have to export ufshcd_auto_hibern8_enable() as it 
is static for now.
Shall do that.

Thanks,

Can Guo.

> > +               ufshcd_release(hba);
> > +               pm_runtime_put(hba->dev);
> > +       }
> >  }
> >
> >  /* Convert Auto-Hibernate Idle Timer register value to microseconds 
> > */ diff --git
> > a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 
> > 525f8e6..f12f5a7
> > 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -6892,9 +6892,6 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
> >         /* UniPro link is active now */
> >         ufshcd_set_link_active(hba);
> >
> > -       /* Enable Auto-Hibernate if configured */
> > -       ufshcd_auto_hibern8_enable(hba);
> > -
> >         ret = ufshcd_verify_dev_init(hba);
> >         if (ret)
> >                 goto out;
> > @@ -6945,6 +6942,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
> >         /* set the state as operational after switching to desired 
> > gear */
> >         hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
> >
> > +       /* Enable Auto-Hibernate if configured */
> > +       ufshcd_auto_hibern8_enable(hba);
> > +
> >         /*
> >          * If we are in error handling context or in power management 
> > callbacks
> >          * context, no need to scan the host @@ -7962,12 +7962,12 @@ 
> > static int
> > ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >         if (hba->clk_scaling.is_allowed)
> >                 ufshcd_resume_clkscaling(hba);
> >
> > -       /* Schedule clock gating in case of no access to UFS device 
> > yet */
> > -       ufshcd_release(hba);
> > -
> >         /* Enable Auto-Hibernate if configured */
> >         ufshcd_auto_hibern8_enable(hba);
> >
> > +       /* Schedule clock gating in case of no access to UFS device 
> > yet */
> > +       ufshcd_release(hba);
> > +
> >         goto out;
> >
> >  set_old_link_state:
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
> > Forum,
> > a Linux Foundation Collaborative Project