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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-scsi@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, Nilesh Javali <njavali@marvell.com>,
        Daniel Wagner <dwagner@suse.de>
Subject: [PATCH 4/4] qla2xxx: Handle incorrect entry_type entries
Date:   Thu, 27 Aug 2020 11:58:29 +0200
Message-Id: <20200827095829.63871-5-dwagner@suse.de>
In-Reply-To: <20200827095829.63871-1-dwagner@suse.de>
References: <20200827095829.63871-1-dwagner@suse.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

It was observed on an ISP8324 16Gb HBA with fw=8.08.203 (d0d5) that
pkt->entry_type was MBX_IOCB_TYPE/0x39 with an sp->type SRB_SCSI_CMD
which is invalid and should not be possible.

A careful code review of the crash dump didn't reveal any short
comings. Reading the entry_type from the crash dump shows the expected
value of STATUS_TYPE/0x03 but the call trace shows that
qla24xx_mbx_iocb_entry() is used.

One possible explanation is when pkt->entry_type is read it doesn't
contain the correct information. That means the driver observes an data
race by the firmware.

Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/scsi/qla2xxx/qla_isr.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index b787643f5031..0c324e88b189 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -3392,6 +3392,31 @@ void qla24xx_nvme_ls4_iocb(struct scsi_qla_host *vha,
 	sp->done(sp, comp_status);
 }
 
+static void qla24xx_process_mbx_iocb_response(struct scsi_qla_host *vha,
+	struct rsp_que *rsp, struct sts_entry_24xx *pkt)
+{
+	srb_t *sp;
+
+	sp = qla2x00_get_sp_from_handle(vha, rsp->req, pkt);
+	if (!sp)
+		return;
+
+	if (sp->type == SRB_SCSI_CMD ||
+	    sp->type == SRB_NVME_CMD ||
+	    sp->type == SRB_TM_CMD) {
+		/* Some firmware version don't update the entry_type
+		 * correctly.  It was observed entry_type contained
+		 * MBCX_IOCB_TYPE instead of the expected STATUS_TYPE
+		 * for sp->type SRB_SCSI_CMD, SRB_NVME_CMD or
+		 * SRB_TM_CMD.
+		 */
+		qla2x00_status_entry(vha, rsp, pkt);
+		return;
+	}
+
+	qla24xx_mbx_iocb_entry(vha, rsp->req, (struct mbx_24xx_entry *)pkt);
+}
+
 /**
  * qla24xx_process_response_queue() - Process response queue entries.
  * @vha: SCSI driver HA context
@@ -3499,8 +3524,7 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
 			    (struct abort_entry_24xx *)pkt);
 			break;
 		case MBX_IOCB_TYPE:
-			qla24xx_mbx_iocb_entry(vha, rsp->req,
-			    (struct mbx_24xx_entry *)pkt);
+			qla24xx_process_mbx_iocb_response(vha, rsp, pkt);
 			break;
 		case VP_CTRL_IOCB_TYPE:
 			qla_ctrlvp_completed(vha, rsp->req,
-- 
2.16.4