Re: [PATCH v1] ufs: core: complete wl runtime resume after SCSI EH

[Bart Van Assche <bvanassche@acm.org>]

On 5/26/26 4:49 AM, Hongjie Fang wrote:
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index c3f08957d179..e7517cf23f06 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -10368,6 +10368,22 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   }
>   
>   #ifdef CONFIG_PM
> +static int ufshcd_wl_resume_pm_recovered(struct ufs_hba *hba)
> +{
> +	int ret = 0;
> +	struct scsi_device *sdp = hba->ufs_device_wlun;
> +
> +	if (!sdp || !scsi_block_when_processing_errors(sdp))
> +		return 0;
> +
> +	if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL &&
> +	    ufshcd_is_link_active(hba) &&
> +	    ufshcd_is_ufs_dev_active(hba))
> +		ret = 1;
> +
> +	return ret;
> +}
> +
>   static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   {
>   	int ret;
> @@ -10422,6 +10438,9 @@ static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   
>   	if (!ufshcd_is_ufs_dev_active(hba)) {
>   		ret = ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE);
> +		if (pm_op == UFS_RUNTIME_PM && ret == -EIO &&
> +		    ufshcd_wl_resume_pm_recovered(hba))
> +			ret = 0;
>   		if (ret)
>   			goto set_old_link_state;
>   		ufshcd_set_timestamp_attr(hba);

This change increases the complexity of the UFS driver too much. Please 
consider building a solution for this issue on top of the (untested)
patch below. The patch below prevents that the SCSI EH is activated if a
START STOP UNIT command times out:

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 9e0336098e26..4be5453efb34 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -9491,7 +9491,7 @@ static enum scsi_timeout_action 
ufshcd_eh_timed_out(struct scsi_cmnd *scmd)
  {
  	struct ufs_hba *hba = shost_priv(scmd->device->host);

-	if (!hba->system_suspending) {
+	if (!hba->pm_op_in_progress) {
  		/* Activate the error handler in the SCSI core. */
  		return SCSI_EH_NOT_HANDLED;
  	}
@@ -10543,7 +10543,6 @@ static int ufshcd_wl_suspend(struct device *dev)

  	hba = shost_priv(sdev->host);
  	down(&hba->host_sem);
-	hba->system_suspending = true;

  	if (pm_runtime_suspended(dev))
  		goto out;
@@ -10585,7 +10584,6 @@ static int ufshcd_wl_resume(struct device *dev)
  		hba->curr_dev_pwr_mode, hba->uic_link_state);
  	if (!ret)
  		hba->is_sys_suspended = false;
-	hba->system_suspending = false;
  	up(&hba->host_sem);
  	return ret;
  }
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 3eaae082329c..248d0a5bef40 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1029,8 +1029,6 @@ enum ufshcd_mcq_opr {
   * @caps: bitmask with information about UFS controller capabilities
   * @devfreq: frequency scaling information owned by the devfreq core
   * @clk_scaling: frequency scaling information owned by the UFS driver
- * @system_suspending: system suspend has been started and system 
resume has
- *	not yet finished.
   * @is_sys_suspended: UFS device has been suspended because of system 
suspend
   * @urgent_bkops_lvl: keeps track of urgent bkops level for device
   * @is_urgent_bkops_lvl_checked: keeps track if the urgent bkops level for
@@ -1206,7 +1204,6 @@ struct ufs_hba {

  	struct devfreq *devfreq;
  	struct ufs_clk_scaling clk_scaling;
-	bool system_suspending;
  	bool is_sys_suspended;

  	enum bkops_status urgent_bkops_lvl;

Thanks,

Bart.