Patch "mailbox: always wait in mbox_send_message for blocking Tx mode" has been added to the 3.18-stable tree

Patch "mailbox: always wait in mbox_send_message for blocking Tx mode" has been added to the 3.18-stable tree

[gregkh]

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

    mailbox: always wait in mbox_send_message for blocking Tx mode

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:
     mailbox-always-wait-in-mbox_send_message-for-blocking-tx-mode.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 <stable@vger.kernel.org> know about it.


>From c61b781ee084e69855477d23dd33e7e6caad652c Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@arm.com>
Date: Tue, 21 Mar 2017 11:30:14 +0000
Subject: mailbox: always wait in mbox_send_message for blocking Tx mode

From: Sudeep Holla <sudeep.holla@arm.com>

commit c61b781ee084e69855477d23dd33e7e6caad652c upstream.

There exists a race when msg_submit return immediately as there was an
active request being processed which may have completed just before it's
checked again in mbox_send_message. This will result in return to the
caller without waiting in mbox_send_message even when it's blocking Tx.

This patch fixes the issue by waiting for the completion always if Tx
is in blocking mode.

Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox")
Reported-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mailbox/mailbox.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -255,7 +255,7 @@ int mbox_send_message(struct mbox_chan *
 	if (chan->txdone_method	== TXDONE_BY_POLL)
 		poll_txdone((unsigned long)chan->mbox);
 
-	if (chan->cl->tx_block && chan->active_req) {
+	if (chan->cl->tx_block) {
 		unsigned long wait;
 		int ret;
 


Patches currently in stable-queue which might be from sudeep.holla@arm.com are

queue-3.18/mailbox-always-wait-in-mbox_send_message-for-blocking-tx-mode.patch
queue-3.18/mailbox-skip-complete-wait-event-if-timer-expired.patch
queue-3.18/mailbox-handle-empty-message-in-tx_tick.patch