[RESEND] [PATCH 1/1] ses: Retry UNIT ATTENTION for receive diagnostics

[RESEND] [PATCH 1/1] ses: Retry UNIT ATTENTION for receive diagnostics

[Brian King]

If the ses driver receives a UNIT ATTENTION when issuing
a receive diagnostics while probing a SES device, it
fails to attach with messages such as:

scsi 1:0:7:0: Failed to get diagnostic page 0x8000002
scsi 1:0:7:0: Failed to bind enclosure -19

Fix this by eating unit attentions for these commands.

Cc: <stable@vger.kernel.org>
Suggested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
---

 drivers/scsi/ses.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff -puN drivers/scsi/ses.c~ses_rcv_diag_retry drivers/scsi/ses.c
--- linux-2.6.git/drivers/scsi/ses.c~ses_rcv_diag_retry	2016-08-25 18:28:18.720565322 -0500
+++ linux-2.6.git-bjking1/drivers/scsi/ses.c	2016-08-25 18:28:29.687496342 -0500
@@ -86,7 +86,7 @@ static void init_device_slot_control(uns
 static int ses_recv_diag(struct scsi_device *sdev, int page_code,
 			 void *buf, int bufflen)
 {
-	int ret;
+	int ret, retries = SES_RETRIES;
 	unsigned char cmd[] = {
 		RECEIVE_DIAGNOSTIC,
 		1,		/* Set PCV bit */
@@ -96,11 +96,14 @@ static int ses_recv_diag(struct scsi_dev
 		0
 	};
 	unsigned char recv_page_code;
+	struct scsi_sense_hdr sshdr;
 
-	ret =  scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, bufflen,
-				NULL, SES_TIMEOUT, SES_RETRIES, NULL);
-	if (unlikely(!ret))
-		return ret;
+	do {
+		memset(&sshdr, 0, sizeof(sshdr));
+		ret =  scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, bufflen,
+					&sshdr, SES_TIMEOUT, retries, NULL);
+	} while (scsi_sense_valid(&sshdr) &&
+		 sshdr.sense_key == UNIT_ATTENTION && --retries);
 
 	recv_page_code = ((unsigned char *)buf)[0];
 
_

Re: [RESEND] [PATCH 1/1] ses: Retry UNIT ATTENTION for receive diagnostics

[Gabriel Krisman Bertazi]

Brian King <brking@linux.vnet.ibm.com> writes:

> If the ses driver receives a UNIT ATTENTION when issuing
> a receive diagnostics while probing a SES device, it
> fails to attach with messages such as:
>
> scsi 1:0:7:0: Failed to get diagnostic page 0x8000002
> scsi 1:0:7:0: Failed to bind enclosure -19
>
> Fix this by eating unit attentions for these commands.


Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>



-- 
Gabriel Krisman Bertazi

Re: [RESEND] [PATCH 1/1] ses: Retry UNIT ATTENTION for receive diagnostics

[Martin K. Petersen]

>>>>> "Brian" == Brian King <brking@linux.vnet.ibm.com> writes:

Brian> If the ses driver receives a UNIT ATTENTION when issuing a
Brian> receive diagnostics while probing a SES device, it fails to
Brian> attach with messages such as:

Brian> scsi 1:0:7:0: Failed to get diagnostic page 0x8000002 scsi
Brian> 1:0:7:0: Failed to bind enclosure -19

Brian> Fix this by eating unit attentions for these commands.

James?

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [RESEND] [PATCH 1/1] ses: Retry UNIT ATTENTION for receive diagnostics

[James Bottomley]

On Mon, 2016-09-19 at 11:57 -0400, Martin K. Petersen wrote:
> > > > > > "Brian" == Brian King <brking@linux.vnet.ibm.com> writes:
> 
> Brian> If the ses driver receives a UNIT ATTENTION when issuing a
> Brian> receive diagnostics while probing a SES device, it fails to
> Brian> attach with messages such as:
> 
> Brian> scsi 1:0:7:0: Failed to get diagnostic page 0x8000002 scsi
> Brian> 1:0:7:0: Failed to bind enclosure -19
> 
> Brian> Fix this by eating unit attentions for these commands.
> 
> James?

It seems to me that UA handling should be a part of scsi_execute_req
(and scsi_execute) ... that is unless anyone can find a caller that
would actually be interested.  I've been looking but haven't found one
so far.

James