[PATCH 1/3] mailbox: always wait in mbox_send_message for blocking Tx mode

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From	Sudeep Holla <sudeep.holla@arm.com>
Newsgroups	linux.kernel
Subject	[PATCH 1/3] mailbox: always wait in mbox_send_message for blocking Tx mode
Date	Tue, 21 Mar 2017 12:40:01 +0100
Message-ID	<tnqiR-2Gb-5@gated-at.bofh.it> (permalink)
X-Original-To	linux-kernel@vger.kernel.org, Jassi Brar <jaswinder.singh@linaro.org>
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X-Original-Cc	Sudeep Holla <sudeep.holla@arm.com>, Alexey Klimov <alexey.klimov@arm.com>, Jassi Brar <jassisinghbrar@gmail.com>
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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")
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Reported-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/mailbox/mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Hi Jassi,

Here are fixes for few issues we encountered when dealing with multiple
requests on multiple channels simultaneously.

Regards,
Sudeep

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 4671f8a12872..160d6640425a 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -260,7 +260,7 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg)

 	msg_submit(chan);

-	if (chan->cl->tx_block && chan->active_req) {
+	if (chan->cl->tx_block) {
 		unsigned long wait;
 		int ret;

--
2.7.4

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[PATCH 1/3] mailbox: always wait in mbox_send_message for blocking Tx mode Sudeep Holla <sudeep.holla@arm.com> - 2017-03-21 12:40 +0100
  [PATCH 2/3] mailbox: skip complete wait event if timer expired Sudeep Holla <sudeep.holla@arm.com> - 2017-03-21 12:40 +0100
  [PATCH 3/3] mailbox: handle empty message in tx_tick Sudeep Holla <sudeep.holla@arm.com> - 2017-03-21 12:40 +0100

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