Commit 5fbd545c authored Aug 17, 2017 by Bart Van Assche Committed by Jens Axboe Aug 18, 2017

skd: Submit requests to firmware before triggering the 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>

parent 7277cc67

drivers/block/skd_main.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}

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