4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bart Van Assche <bart.vanass...@wdc.com>
commit 5fbd545cd3fd311ea1d6e8be4cedddd0ee5684c7 upstream.
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.vanass...@wdc.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Hannes Reinecke <h...@suse.de>
Cc: Johannes Thumshirn <jthumsh...@suse.de>
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/block/skd_main.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -2214,6 +2214,9 @@ static void skd_send_fitmsg(struct skd_d
*/
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);
}
@@ -2260,6 +2263,9 @@ static void skd_send_special_fitmsg(stru
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);
}
