diff mbox

[v2,04/10] scsi: ufs: fix exception event handling

Message ID 01e6421c38e4eb1f67f3c98a8dab44a85f791ef2.1525343531.git.asutoshd@codeaurora.org (mailing list archive)
State Superseded, archived
Delegated to: Andy Gross
Headers show

Commit Message

Asutosh Das (asd) May 3, 2018, 11:07 a.m. UTC 
From: Maya Erez <merez@codeaurora.org>

The device can set the exception event bit in one of the response UPIU,
for example to notify the need for urgent BKOPs operation.
In such a case the host driver calls ufshcd_exception_event_handler to
handle this notification.
When trying to check the exception event status (for finding the cause for
the exception event), the device may be busy with additional SCSI commands
handling and may not respond within the 100ms timeout.

To prevent that, we need to block SCSI commands during handling of
exception events and allow retransmissions of the query requests,
in case of timeout.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

subhashj@codeaurora.org May 16, 2018, 9:12 p.m. UTC | #1 
On 2018-05-03 04:07, Asutosh Das wrote:
> From: Maya Erez <merez@codeaurora.org>
> 
> The device can set the exception event bit in one of the response UPIU,
> for example to notify the need for urgent BKOPs operation.
> In such a case the host driver calls ufshcd_exception_event_handler to
> handle this notification.
> When trying to check the exception event status (for finding the cause 
> for
> the exception event), the device may be busy with additional SCSI 
> commands
> handling and may not respond within the 100ms timeout.
> 
> To prevent that, we need to block SCSI commands during handling of
> exception events and allow retransmissions of the query requests,
> in case of timeout.
> 
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Maya Erez <merez@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 6dabce8..838ba8f0 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4967,6 +4967,7 @@ static void
> ufshcd_exception_event_handler(struct work_struct *work)
>  	hba = container_of(work, struct ufs_hba, eeh_work);
> 
>  	pm_runtime_get_sync(hba->dev);
> +	scsi_block_requests(hba->host);
>  	err = ufshcd_get_ee_status(hba, &status);
>  	if (err) {
>  		dev_err(hba->dev, "%s: failed to get exception status %d\n",
> @@ -4980,6 +4981,7 @@ static void
> ufshcd_exception_event_handler(struct work_struct *work)
>  		ufshcd_bkops_exception_event_handler(hba);
> 
>  out:
> +	scsi_unblock_requests(hba->host);
>  	pm_runtime_put_sync(hba->dev);
>  	return;
>  }

Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
diff mbox

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 6dabce8..838ba8f0 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4967,6 +4967,7 @@  static void ufshcd_exception_event_handler(struct work_struct *work)
 	hba = container_of(work, struct ufs_hba, eeh_work);
 
 	pm_runtime_get_sync(hba->dev);
+	scsi_block_requests(hba->host);
 	err = ufshcd_get_ee_status(hba, &status);
 	if (err) {
 		dev_err(hba->dev, "%s: failed to get exception status %d\n",
@@ -4980,6 +4981,7 @@  static void ufshcd_exception_event_handler(struct work_struct *work)
 		ufshcd_bkops_exception_event_handler(hba);
 
 out:
+	scsi_unblock_requests(hba->host);
 	pm_runtime_put_sync(hba->dev);
 	return;
 }