From 96cf727fe8f102bf92150b741db71ee39fb8c521 Mon Sep 17 00:00:00 2001
From: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Date: Wed, 3 Jan 2018 16:54:02 -0600
Subject: [PATCH] scsi: cxlflash: Reset command ioasc

References: fate#322239, git-fixes
Patch-mainline: v4.16-rc1
Git-commit: 96cf727fe8f102bf92150b741db71ee39fb8c521

In the event of a command failure, cxlflash returns the failure to the upper
layers to process. After processing the error, when the command is queued
again, the private command structure will not be zeroed and the ioasc could be
stale. Per the SISLite specification, the AFU only sets the ioasc in the
presence of a failure. Thus, even though the original command succeeds the
second time, the command is considered a failure due to stale ioasc. This
cycle repeats indefinitely and can cause a hang or IO failure.

To fix the issue, clear the ioasc before queuing any command.

[mkp: added Cc: stable per request]

Fixes: 479ad8e9d48c ("scsi: cxlflash: Remove zeroing of private command data")
Cc: <stable@vger.kernel.org>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/scsi/cxlflash/main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 38b3a9c84fd1..48d366304582 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -620,6 +620,7 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
 	cmd->parent = afu;
 	cmd->hwq_index = hwq_index;
 
+	cmd->sa.ioasc = 0;
 	cmd->rcb.ctx_id = hwq->ctx_hndl;
 	cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
 	cmd->rcb.port_sel = CHAN2PORTMASK(scp->device->channel);
-- 
2.13.6