Re: [PATCH v2] scsi: ufs: disable auto hibern8 while entering suspend

Stanley Chu
2022-01-26T01:22:36Z

Hi Hoyoung,

On Tue, 2022-01-25 at 03:06 +0900, SEO HOYOUNG wrote:
> v1-> v2: fixed no previous prototype warning
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
> > > drivers/scsi/ufs/ufshcd.c:4207:6: warning: no previous prototype
>
> for 'ufshcd_auto_hibern8_disable' [-Wmissing-prototypes]
> 4207 | void ufshcd_auto_hibern8_disable(struct ufs_hba *hba)
>
> If using auto hibern8 mode, need to disable auto hibern8 while
> entering suspend.
> When using auto hibern8 mode, it does not seem right to send a uic
> command

The UFSHCI spec does not mention the above rule.
Why would you need to disable AH8 before using UIC command to enter H8?

> for entry into hibern8 in the next
> line(ufshcd_lik_state_transition(..))
> It seem right to send after disable auto hibern8.
>
> In addition, if the auto hibern8 mode supported, it is enabled in
> resume.
> So it seems that it will be paired only when auto hibern8 is disabled
> while entering suspend.
>
> Signed-off-by: SEO HOYOUNG <hy50.seo@samsung.com>
> ---
> drivers/scsi/ufs/ufshcd.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 460d2b440d2e..a6edbbd8ca2c 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -254,6 +254,7 @@ static void
> ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set);
> static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool
> enable);
> static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
> static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba);
> +static void ufshcd_auto_hibern8_disable(struct ufs_hba *hba);
>
> static inline void ufshcd_enable_irq(struct ufs_hba *hba)
> {
> @@ -4204,6 +4205,18 @@ void ufshcd_auto_hibern8_update(struct ufs_hba
> *hba, u32 ahit)
> }
> EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
>
> +static void ufshcd_auto_hibern8_disable(struct ufs_hba *hba)
> +{
> + unsigned long flags;
> +
> + if (!ufshcd_is_auto_hibern8_supported(hba))
> + return;
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + ufshcd_writel(hba, 0, REG_AUTO_HIBERNATE_IDLE_TIMER);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +}
> +
> void ufshcd_auto_hibern8_enable(struct ufs_hba *hba)
> {
> unsigned long flags;
> @@ -8925,6 +8938,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba
> *hba, enum ufs_pm_op pm_op)
> * with the link off, so do not check for bkops.
> */
> check_for_bkops = !ufshcd_is_ufs_dev_deepsleep(hba);
> + ufshcd_auto_hibern8_disable(hba);
> ret = ufshcd_link_state_transition(hba, req_link_state,
> check_for_bkops);
> if (ret)
> goto set_dev_active;