Re: [PATCH v2 1/2] scsi: ufs: Abort tasks before clear them from doorbell

[Stanley Chu]

Hi James,

On Wed, 2020-09-09 at 23:18 -0700, James Bottomley wrote:
> On Thu, 2020-09-10 at 10:48 +0800, Stanley Chu wrote:
> > Hi Martin, Can,
> > 
> > On Wed, 2020-09-09 at 22:32 -0400, Martin K. Petersen wrote:
> > > Can and Stanley,
> > > 
> > > > I can't reconcile this hunk:
> > > 
> > > Please provide a resolution for these conflicting commits in fixes
> > > and
> > > queue:
> > > 
> > > 307348f6ab14 scsi: ufs: Abort tasks before clearing them from
> > > doorbell
> > > 
> > > b10178ee7fa8 scsi: ufs: Clean up completed request without
> > > interrupt
> > > notification
> > > 
> > 
> > Can's patch has considered my fix in the new flow.
> > 
> > To be more clear, for the fixing case in my patch,
> > ufshcd_try_to_abort_task() will return 0 (err = 0) and finally the
> > target tag can be completed and cleared by
> > __ufshcd_transfer_req_compl()
> > in Can's new flow.
> > 
> > Thus I think the resolution can just using the code in Can's patch.
> > 
> > Can, please correct me if I was wrong.
> 
> Well, that really doesn't make for an easy merge. The resolution I took
> is below.
> 
> James
> 
> ---
> 
> commit 5399a4aa684d491c35a386effe385c06b41398fa
> Merge: 59958f7a956b 8c6572356646
> Author: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> Date:   Wed Sep 9 23:12:52 2020 -0700
> 
>     Merge branch 'misc' into for-next
>     
>     Conflicts:
>             drivers/scsi/ufs/ufshcd.c
>             drivers/scsi/ufs/ufshcd.h
> 
> diff --cc drivers/scsi/ufs/ufshcd.c
> index 34e1ab407b05,05716f62febe..49478c8a601f
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@@ -6574,84 -6739,22 +6736,25 @@@ static int ufshcd_abort(struct scsi_cmn
>   	}
>   	hba->req_abort_count++;
>   
>  -	/* Skip task abort in case previous aborts failed and report failure */
>  -	if (lrbp->req_abort_skip) {
>  -		err = -EIO;
>  -		goto out;
>  +	if (!(reg & (1 << tag))) {
>  +		dev_err(hba->dev,
>  +		"%s: cmd was completed, but without a notifying intr, tag = %d",
>  +		__func__, tag);
>  +		goto cleanup;
>   	}
>   
>  -	err = ufshcd_try_to_abort_task(hba, tag);
>  -	if (err)
>  -		goto out;
>  -
>  -	spin_lock_irqsave(host->host_lock, flags);
>  -	__ufshcd_transfer_req_compl(hba, (1UL << tag));
>  -	spin_unlock_irqrestore(host->host_lock, flags);
>  +	/* Skip task abort in case previous aborts failed and report failure */
> - 	if (lrbp->req_abort_skip) {
> ++	if (lrbp->req_abort_skip)
>  +		err = -EIO;
> - 		goto out;
> - 	}
> - 
> - 	for (poll_cnt = 100; poll_cnt; poll_cnt--) {
> - 		err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
> - 				UFS_QUERY_TASK, &resp);
> - 		if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED) {
> - 			/* cmd pending in the device */
> - 			dev_err(hba->dev, "%s: cmd pending in the device. tag = %d\n",
> - 				__func__, tag);
> - 			break;
> - 		} else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
> - 			/*
> - 			 * cmd not pending in the device, check if it is
> - 			 * in transition.
> - 			 */
> - 			dev_err(hba->dev, "%s: cmd at tag %d not pending in the device.\n",
> - 				__func__, tag);
> - 			reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
> - 			if (reg & (1 << tag)) {
> - 				/* sleep for max. 200us to stabilize */
> - 				usleep_range(100, 200);
> - 				continue;
> - 			}
> - 			/* command completed already */
> - 			dev_err(hba->dev, "%s: cmd at tag %d successfully cleared from DB.\n",
> - 				__func__, tag);
> - 			goto cleanup;
> - 		} else {
> - 			dev_err(hba->dev,
> - 				"%s: no response from device. tag = %d, err %d\n",
> - 				__func__, tag, err);
> - 			if (!err)
> - 				err = resp; /* service response error */
> - 			goto out;
> - 		}
> - 	}
> - 
> - 	if (!poll_cnt) {
> - 		err = -EBUSY;
> - 		goto out;
> - 	}
> - 
> - 	err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
> - 			UFS_ABORT_TASK, &resp);
> - 	if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
> - 		if (!err) {
> - 			err = resp; /* service response error */
> - 			dev_err(hba->dev, "%s: issued. tag = %d, err %d\n",
> - 				__func__, tag, err);
> - 		}
> - 		goto out;
> - 	}
> - 
> - 	err = ufshcd_clear_cmd(hba, tag);
> - 	if (err) {
> - 		dev_err(hba->dev, "%s: Failed clearing cmd at tag %d, err %d\n",
> - 			__func__, tag, err);
> - 		goto out;
> - 	}
> ++	else
> ++		err = ufshcd_try_to_abort_task(hba, tag);
>   
>  -out:
> + 	if (!err) {
>  +cleanup:

Yeah, considering Bean Huo's patch "scsi: ufs: No need to send Abort
Task if the task in DB was cleared", "cleanup" label shall be added back
here.

So your resolution looks good to me.

Thanks so much : )

Stanley Chu

> - 	spin_lock_irqsave(host->host_lock, flags);
> - 	__ufshcd_transfer_req_compl(hba, (1UL << tag));
> - 	spin_unlock_irqrestore(host->host_lock, flags);
> - 
> ++		spin_lock_irqsave(host->host_lock, flags);
> ++		__ufshcd_transfer_req_compl(hba, (1UL << tag));
> ++		spin_unlock_irqrestore(host->host_lock, flags);
>  +out:
> - 	if (!err) {
>   		err = SUCCESS;
>   	} else {
>   		dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
> diff --cc drivers/scsi/ufs/ufshcd.h
> index b5b2761456fb,8011fdc89fb1..6663325ed8a0
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@@ -531,11 -531,10 +531,16 @@@ enum ufshcd_quirks 
>   	 */
>   	UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR		= 1 << 10,
>   
>  +	/*
>  +	 * This quirk needs to be enabled if the host controller has
>  +	 * auto-hibernate capability but it doesn't work.
>  +	 */
>  +	UFSHCD_QUIRK_BROKEN_AUTO_HIBERN8		= 1 << 11,
> ++
> + 	/*
> + 	 * This quirk needs to disable manual flush for write booster
> + 	 */
>  -	UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL		= 1 << 11,
> ++	UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL		= 1 << 12,
>   };
>   
>   enum ufshcd_caps {