3.16.51-rc1 review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche bart.vanassche@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.vanassche@wdc.com Cc: Christoph Hellwig hch@lst.de Cc: Hannes Reinecke hare@suse.de Cc: Johannes Thumshirn jthumshirn@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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); }