[PATCH 1/2] scsi: ufs: retry START_STOP on UNIT_ATTENTION

Jaegeuk Kim
2021-10-01T18:20:36Z

Commit 57d104c153d3 ("ufs: add UFS power management support") made the UFS
driver submit a REQUEST SENSE command before submitting a power management
command to a WLUN to clear the POWER ON unit attention. Instead of
submitting a REQUEST SENSE command before submitting a power management
command, retry the power management command until it succeeds.

This is the preparation to get rid of all UNIT ATTENTION code which should
be handled by users.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
drivers/scsi/ufs/ufshcd.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 9faf02cbb9ad..7ec72de826e5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8676,7 +8676,7 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
struct scsi_sense_hdr sshdr;
struct scsi_device *sdp;
unsigned long flags;
- int ret;
+ int ret, retries;

spin_lock_irqsave(hba->host->host_lock, flags);
sdp = hba->sdev_ufs_device;
@@ -8711,8 +8711,14 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
* callbacks hence set the RQF_PM flag so that it doesn't resume the
* already suspended childs.
*/
- ret = scsi_execute(sdp, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
- START_STOP_TIMEOUT, 0, 0, RQF_PM, NULL);
+ for (retries = 3; retries > 0; --retries) {
+ ret = scsi_execute(sdp, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
+ START_STOP_TIMEOUT, 0, 0, RQF_PM, NULL);
+ if (!scsi_status_is_check_condition(ret) ||
+ !scsi_sense_valid(&sshdr) ||
+ sshdr.sense_key != UNIT_ATTENTION)
+ break;
+ }
if (ret) {
sdev_printk(KERN_WARNING, sdp,
"START_STOP failed for power mode: %d, result %x\n",
--
2.33.0.800.g4c38ced690-goog