[PATCH v1] ufs: core: wlun suspend SSU fail recovery

[Adrian Hunter]

On 1/11/22 16:24, peter.wang at mediatek.com wrote:
> From: Peter Wang <peter.wang at mediatek.com>
> 
> When SSU fail in wlun suspend flow, trigger error handlder and

handlder -> handler

Why / how does SSU fail?

> return busy to break the suspend.
> If not, wlun runtime pm status become error and the consumer will
> stuck in runtime suspend status.
> 
> Signed-off-by: Peter Wang <peter.wang at mediatek.com>
> ---
>  drivers/ufs/core/ufshcd.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index b1f59a5fe632..2f2d3d5d8684 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -8970,6 +8970,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	enum ufs_pm_level pm_lvl;
>  	enum ufs_dev_pwr_mode req_dev_pwr_mode;
>  	enum uic_link_state req_link_state;
> +	unsigned long flags;
>  
>  	hba->pm_op_in_progress = true;
>  	if (pm_op != UFS_SHUTDOWN_PM) {
> @@ -9049,8 +9050,21 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  
>  		if (!hba->dev_info.b_rpm_dev_flush_capable) {
>  			ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
> -			if (ret)
> +			if (ret) {
> +				/*
> +				 * If retrun err in suspend flow, IO will hang.

retrun -> return

> +				 * Trigger error handler and break suspend for
> +				 * error recovery.
> +				 */
> +				spin_lock_irqsave(hba->host->host_lock, flags);
> +				hba->force_reset = true;
> +				ufshcd_schedule_eh_work(hba);

__ufshcd_wl_suspend() is also used for shutdown and poweroff
where scheduling EH is not appropriate.

> +				spin_unlock_irqrestore(hba->host->host_lock,
> +					flags);
> +
> +				ret = -EBUSY;
>  				goto enable_scaling;
> +			}
>  		}
>  	}
>