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

[Avri Altman]

> 
> 
> 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? 

> +               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:
> --
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