[PATCHv3 4/6] mailbox: Fix TX completion init

Jassi Brar
2014-02-15T18:26:28Z

From: LeyFoon Tan <lftan.linux@gmail.com>

For fast TX the complete could be called before being initialized as follows
ipc_send_message --> poll_txdone --> tx_tick --> complete(&chan->tx_complete)

Init the completion early enough to fix the race.

Signed-off-by: LeyFoon Tan <lftan.linux@gmail.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
drivers/mailbox/mailbox.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 3082f08..f8b31da 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -258,6 +258,9 @@ request_token_t ipc_send_message(void *channel, void *mssg)
if (!chan || !chan->assigned)
return 0;

+ if (chan->tx_block)
+ init_completion(&chan->tx_complete);
+
t = _add_to_rbuf(chan, mssg);
if (!t)
pr_err("Try increasing MBOX_TX_QUEUE_LEN\n");
@@ -269,7 +272,6 @@ request_token_t ipc_send_message(void *channel, void *mssg)

if (chan->tx_block && chan->active_req) {
int ret;
- init_completion(&chan->tx_complete);
ret = wait_for_completion_timeout(&chan->tx_complete,
chan->tx_tout);
if (ret == 0) {
--
1.8.1.2