[PATCH v1] scsi: ufs: Cleanup completed request without interrupt notification

Stanley Chu stanley.chu at mediatek.com
Tue Jun 23 05:05:11 EDT 2020

If somehow no interrupt notification is raised for a completed request
and its doorbell bit is cleared by host, UFS driver needs to cleanup
its outstanding bit in ufshcd_abort().

Otherwise, system may crash by below abnormal flow:

After this request is requeued by SCSI layer with its
outstanding bit set, the next completed request will trigger
ufshcd_transfer_req_compl() to handle all "completed outstanding
bits". In this time, the "abnormal outstanding bit" will be detected
and the "requeued request" will be chosen to execute request
post-processing flow. This is wrong and blk_finish_request() will
BUG_ON because this request is still in the request queue.

Signed-off-by: Stanley Chu <stanley.chu at mediatek.com>
 drivers/scsi/ufs/ufshcd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 52abe82a1166..f173ad1bd79f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6462,7 +6462,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 			/* command completed already */
 			dev_err(hba->dev, "%s: cmd at tag %d successfully cleared from DB.\n",
 				__func__, tag);
-			goto out;
+			goto cleanup;
 		} else {
 				"%s: no response from device. tag = %d, err %d\n",
@@ -6496,6 +6496,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 		goto out;
 	spin_lock_irqsave(host->host_lock, flags);

More information about the linux-arm-kernel mailing list