From:   Adrian Hunter <adrian.hunter@intel.com>
To:     stable@vger.kernel.org
Subject: [PATCH 5.15] scsi: ufs: core: Retry START_STOP on UNIT_ATTENTION
Date:   Thu, 16 Dec 2021 12:07:49 +0200
Message-Id: <20211216100749.202131-1-adrian.hunter@intel.com>
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Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki
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From: Jaegeuk Kim <jaegeuk@kernel.org>

commit af21c3fd5b3ec540a97b367a70b26616ff7e0c55 upstream.

Note for stable: This patch is required if commit edc0596cc04bf ("scsi:
ufs: core: Stop clearing UNIT ATTENTIONS") has been cherry-picked.

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>
[Adrian: For stable]
Signed-off-by: Adrian Hunter <adrian.hunter@intel.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 55f2e4d6f10b..31adf25e57b0 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8477,7 +8477,7 @@ 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;
@@ -8510,8 +8510,14 @@ 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",
-- 
2.25.1