[PATCH v5 2/6] ufs: surface sense data from ufs_scsi_exec()

[Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>]

On a CHECK CONDITION the UFS device returns SCSI sense data inline in the
RESPONSE UPIU, but ufs_scsi_exec() discarded it and reported every
failure as a bare -EINVAL, leaving callers unable to tell a transient
condition such as a power-on UNIT ATTENTION from a hard error.

Preserve the sense data and SCSI status in the scsi_cmd. No caller
inspects them yet, so behaviour is unchanged.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
---
 drivers/ufs/ufs-uclass.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/ufs-uclass.c b/drivers/ufs/ufs-uclass.c
index 21aed9f97bd..3d96a05281c 100644
--- a/drivers/ufs/ufs-uclass.c
+++ b/drivers/ufs/ufs-uclass.c
@@ -1657,6 +1657,22 @@ static void prepare_prdt_table(struct ufs_hba *hba, struct scsi_cmd *pccb)
 	ufshcd_cache_flush(req_desc, sizeof(*req_desc));
 }
 
+/*
+ * On a CHECK CONDITION the sense data is returned inline in the RESPONSE
+ * UPIU; copy it into the SCSI command so callers can inspect the sense key
+ * (for example to tell a transient UNIT ATTENTION from a hard error).
+ */
+static void ufs_scsi_copy_sense(struct ufs_hba *hba, struct scsi_cmd *pccb)
+{
+	u16 len = be16_to_cpu(hba->ucd_rsp_ptr->sr.sense_data_len);
+
+	if (len > RESPONSE_UPIU_SENSE_DATA_LENGTH)
+		len = RESPONSE_UPIU_SENSE_DATA_LENGTH;
+
+	memcpy(pccb->sense_buf, hba->ucd_rsp_ptr->sr.sense_data, len);
+	pccb->sensedatalen = len;
+}
+
 static int ufs_scsi_exec(struct udevice *scsi_dev, struct scsi_cmd *pccb)
 {
 	struct ufs_hba *hba = dev_get_uclass_priv(scsi_dev->parent);
@@ -1664,6 +1680,9 @@ static int ufs_scsi_exec(struct udevice *scsi_dev, struct scsi_cmd *pccb)
 	int ocs, result = 0;
 	u8 scsi_status;
 
+	pccb->status = 0;
+	pccb->sensedatalen = 0;
+
 	ufshcd_prepare_req_desc_hdr(hba, &upiu_flags, pccb->dma_dir);
 	ufshcd_prepare_utp_scsi_cmd_upiu(hba, pccb, upiu_flags);
 	prepare_prdt_table(hba, pccb);
@@ -1683,8 +1702,12 @@ static int ufs_scsi_exec(struct udevice *scsi_dev, struct scsi_cmd *pccb)
 			result = ufshcd_get_rsp_upiu_result(hba->ucd_rsp_ptr);
 
 			scsi_status = result & MASK_SCSI_STATUS;
-			if (scsi_status)
+			if (scsi_status) {
+				pccb->status = scsi_status;
+				if (scsi_status == S_CHECK_COND)
+					ufs_scsi_copy_sense(hba, pccb);
 				return -EINVAL;
+			}
 
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
-- 
2.54.0