From: James Smart <jsmart2021@gmail.com>
Date: Tue, 21 May 2019 17:49:07 -0700
Subject: [PATCH] scsi: lpfc: Fix fcp_rsp_len checking on lun reset
References: bsc#1136217,jsc#SLE-4722
Git-commit: 996a02aeb959414378ea6c620934450944f8c5db
Patch-mainline: v5.3-rc1

Issuing a LUN reset was resulting in a command failure which then escalated
to a host reset.

The FCP-4 spec allows fcp_rsp_len field to specify the number of valid
bytes of FCP_RSP_INFO, and the value could be 4 or 8.  The driver is
allowing only a value of 8, thus it failed the command.

Revise the driver to allow 4 or 8.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/lpfc/lpfc_scsi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 6640a13ca1fb..4436090bfe33 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -4798,7 +4798,12 @@ lpfc_check_fcp_rsp(struct lpfc_vport *vport, struct lpfc_io_buf *lpfc_cmd)
 				 rsp_info,
 				 rsp_len, rsp_info_code);
 
-		if ((fcprsp->rspStatus2&RSP_LEN_VALID) && (rsp_len == 8)) {
+		/* If FCP_RSP_LEN_VALID bit is one, then the FCP_RSP_LEN
+		 * field specifies the number of valid bytes of FCP_RSP_INFO.
+		 * The FCP_RSP_LEN field shall be set to 0x04 or 0x08
+		 */
+		if ((fcprsp->rspStatus2 & RSP_LEN_VALID) &&
+		    ((rsp_len == 8) || (rsp_len == 4))) {
 			switch (rsp_info_code) {
 			case RSP_NO_FAILURE:
 				lpfc_printf_vlog(vport, KERN_INFO, LOG_FCP,
-- 
2.16.4