[PATCH 4.19 073/125] scsi: ufs: Clean up completed request without interrupt notification

Greg Kroah-Hartman
2020-09-01T16:44:33Z

From: Stanley Chu <stanley.chu@mediatek.com>

[ Upstream commit b10178ee7fa88b68a9e8adc06534d2605cb0ec23 ]

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
in the following scenario:

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". At
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".

Link: https://lore.kernel.org/r/20200811141859.27399-2-huobean@gmail.com
Reviewed-by: Can Guo <cang@codeaurora.org>
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 d8c6fd2012757..eb10a5cacd90c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5930,7 +5930,7 @@ 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",
@@ -5964,6 +5964,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
goto out;
}

+cleanup:
scsi_dma_unmap(cmd);

spin_lock_irqsave(host->host_lock, flags);
--
2.25.1