[PATCH v4 1/2] ufs: rpmb: retry power-on UNIT ATTENTION on the RPMB WLUN

[Jorge Ramirez-Ortiz]

After a power cycle, the first command sent to any UFS logical unit
completes with CHECK CONDITION reporting a power-on UNIT ATTENTION.
The SCSI core surfaces this condition to the caller rather than
retrying it.

For the RPMB well-known LU the first command after boot is the first
RPMB frame, and RPMB has no earlier, guaranteed access that could clear
the condition beforehand. The power-on UNIT ATTENTION therefore reaches
RPMB and fails that first frame, breaking RPMB on every cold boot.

The RPMB WLUN needs the power-on UNIT ATTENTION to be retried so that
RPMB works from the very first access after a power cycle.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@xxxxxxxxxxxxxxxx>
---
 drivers/ufs/core/ufs-rpmb.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
index ffad049872b9..79e6cd2b20a0 100644
--- a/drivers/ufs/core/ufs-rpmb.c
+++ b/drivers/ufs/core/ufs-rpmb.c
@@ -21,6 +21,7 @@
 #include <linux/unaligned.h>
 #include "ufshcd-priv.h"
 
+#define UFS_RPMB_UA_RETRIES		3	/* Retries for the power-on UNIT ATTENTION */
 #define UFS_RPMB_SEC_PROTOCOL		0xEC	/* JEDEC UFS application */
 #define UFS_RPMB_SEC_PROTOCOL_ID	0x01	/* JEDEC UFS RPMB protocol ID, CDB byte3 */
 
@@ -40,6 +41,22 @@ struct ufs_rpmb_dev {
 static int ufs_sec_submit(struct ufs_hba *hba, u16 spsp, void *buffer, size_t len, bool send)
 {
 	struct scsi_device *sdev = hba->ufs_rpmb_wlun;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,	/* power on, reset, or bus device reset occurred */
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = UFS_RPMB_UA_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
+	const struct scsi_exec_args exec_args = {
+		.failures = &failures,
+	};
 	u8 cdb[12] = { };
 
 	cdb[0] = send ? SECURITY_PROTOCOL_OUT : SECURITY_PROTOCOL_IN;
@@ -48,7 +65,8 @@ static int ufs_sec_submit(struct ufs_hba *hba, u16 spsp, void *buffer, size_t le
 	put_unaligned_be32(len, &cdb[6]);
 
 	return scsi_execute_cmd(sdev, cdb, send ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
-				buffer, len, /*timeout=*/30 * HZ, 0, NULL);
+				buffer, len, /*timeout=*/30 * HZ, /*retries=*/0,
+				&exec_args);
 }
 
 /* UFS RPMB route frames implementation */
-- 
2.54.0