[PATCH v2 2/2] sd: Retry START STOP UNIT commands

[Bart Van Assche <bvanassche@acm.org>]

During system resume, sd_start_stop_device() submits a START STOP UNIT
command to the SCSI device that is being resumed. That command is not
retried in case of a unit attention and hence may fail. An example:

[16575.983359] sd 0:0:0:3: [sdd] Starting disk
[16575.983693] sd 0:0:0:3: [sdd] Start/Stop Unit failed: Result: hostbyte=0x00 driverbyte=DRIVER_OK
[16575.983712] sd 0:0:0:3: [sdd] Sense Key : 0x6
[16575.983730] sd 0:0:0:3: [sdd] ASC=0x29 ASCQ=0x0
[16575.983738] sd 0:0:0:3: PM: dpm_run_callback(): scsi_bus_resume+0x0/0xa0 returns -5
[16575.983783] sd 0:0:0:3: PM: failed to resume async: error -5

Make the SCSI core retry the START STOP UNIT command if a retryable
error is encountered.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/sd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 718eb91ba9a5..4cbf3e5740e1 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -4093,6 +4093,7 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
 		.req_flags = BLK_MQ_REQ_PM,
+		.scmd_flags = SCMD_RETRY_PASSTHROUGH,
 	};
 	struct scsi_device *sdp = sdkp->device;
 	int res;