Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Uma Krishnan <ukrishn@linux.vnet.ibm.com>,
        "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 4.14 195/195] scsi: cxlflash: Reset command ioasc
Date:   Thu, 15 Feb 2018 16:18:06 +0100
Message-Id: <20180215151716.146947676@linuxfoundation.org>
In-Reply-To: <20180215151705.738773577@linuxfoundation.org>
References: <20180215151705.738773577@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Uma Krishnan <ukrishn@linux.vnet.ibm.com>

commit 96cf727fe8f102bf92150b741db71ee39fb8c521 upstream.

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")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/cxlflash/main.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -620,6 +620,7 @@ static int cxlflash_queuecommand(struct
 	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);