[PATCH V2 1/1] scsi/ses: Saw "Failed to get diagnostic page 0x1"

[wenxiong@linux.vnet.ibm.com]

From: Wen Xiong <root@ltczz405-lp2.aus.stglabs.ibm.com>

We saw two errors with Slider drawer:
- Failed to get diagnostic page 0x1 during booting up
- /sys/class/enclosure is empty with ipr adapter + Slider drawer

From scsi logging level with error=3, looks ses_recv_diag not try on a UA.
The patch addes retrying on a UA in ses_recv_diag();

Signed-Off-by: Wen Xiong<wenxiong@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
---
 drivers/scsi/ses.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index c2afba2a5414..93f6a8ce1bea 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -87,9 +87,16 @@ static int ses_recv_diag(struct scsi_device *sdev, int page_code,
 		0
 	};
 	unsigned char recv_page_code;
+	struct scsi_sense_hdr sshdr;
+	int retries = SES_RETRIES;
+
+	do {
+		ret =  scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf,
+			bufflen, &sshdr, NULL, SES_TIMEOUT, SES_RETRIES, NULL);
+
+	} while (scsi_sense_valid(&sshdr) &&
+                 sshdr.sense_key == UNIT_ATTENTION && --retries);
 
-	ret =  scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, bufflen,
-				NULL, SES_TIMEOUT, SES_RETRIES, NULL);
 	if (unlikely(ret))
 		return ret;
 
-- 
2.27.0