[PATCH v4] scsi: ufs: Cleanup completed request without interrupt notification

Stanley Chu
2020-07-24T14:02:54Z

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 behave
abnormally by below flow:

After ufshcd_abort() returns, this request will be requeued by SCSI
layer with its outstanding bit set. Any future 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 because this request is
still "alive".

Signed-off-by: Stanley Chu <stanley.chu@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 577cc0d7487f..9d180da77488 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6493,7 +6493,7 @@ 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 {
dev_err(hba->dev,
"%s: no response from device. tag = %d, err %d\n",
@@ -6527,6 +6527,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
goto out;
}

+cleanup:
scsi_dma_unmap(cmd);

spin_lock_irqsave(host->host_lock, flags);
--
2.18.0