Patch "skd: Submit requests to firmware before triggering the doorbell" has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

skd: Submit requests to firmware before triggering the doorbell

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
skd-submit-requests-to-firmware-before-triggering-the-doorbell.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Bart Van Assche <[email protected]>
Date: Thu, 17 Aug 2017 13:12:46 -0700
Subject: skd: Submit requests to firmware before triggering the doorbell

From: Bart Van Assche <[email protected]>

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

---
 drivers/block/skd_main.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -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);
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/skd-submit-requests-to-firmware-before-triggering-the-doorbell.patch queue-3.18/block-relax-a-check-in-blk_start_queue.patch queue-3.18/skd-avoid-that-module-unloading-triggers-a-use-after-free.patch