From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Thu, 17 Aug 2017 13:12:46 -0700
Subject: [PATCH] skd: Submit requests to firmware before triggering the
Git-commit: 5fbd545cd3fd311ea1d6e8be4cedddd0ee5684c7
Patch-mainline: v4.14-rc1
References: bsc#1104967,FATE#325924
doorbell
Ensure that the members of struct skd_msg_buf have been transferred
to the PCIe adapter before the doorbell is triggered. This patch
avoids that I/O fails sporadically and that the following error
message is reported:
(skd0:STM000196603:[0000:00:09.0]): Completion mismatch comp_id=0x0000 skreq=0x0400 new=0x0000
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/block/skd_main.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index edab9c04e8ad..153f20ce318b 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -2160,6 +2160,9 @@ static void skd_send_fitmsg(struct skd_device *skdev,
*/
qcmd |= FIT_QCMD_MSGSIZE_64;
+ /* Make sure skd_msg_buf is written before the doorbell is triggered. */
+ smp_wmb();
+
SKD_WRITEQ(skdev, qcmd, FIT_Q_COMMAND);
}
@@ -2202,6 +2205,9 @@ static void skd_send_special_fitmsg(struct skd_device *skdev,
qcmd = skspcl->mb_dma_address;
qcmd |= FIT_QCMD_QID_NORMAL + FIT_QCMD_MSGSIZE_128;
+ /* Make sure skd_msg_buf is written before the doorbell is triggered. */
+ smp_wmb();
+
SKD_WRITEQ(skdev, qcmd, FIT_Q_COMMAND);
}
--
2.16.4