From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Fri, 1 Oct 2021 11:20:14 -0700
Subject: scsi: ufs: core: Retry START_STOP on UNIT_ATTENTION
Git-commit: af21c3fd5b3ec540a97b367a70b26616ff7e0c55
Patch-mainline: v5.16-rc1
References: git-fixes

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.

Link: https://lore.kernel.org/r/20211001182015.1347587-2-jaegeuk@kernel.org
Cc: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 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 7126b7a88b56..db5f375d89c5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8675,7 +8675,7 @@ 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;
@@ -8710,8 +8710,14 @@ 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",