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

[Alexey Klimov <alexey.klimov@arm.com>]

On Tue, Mar 21, 2017 at 11:30:14AM +0000, Sudeep Holla wrote:
> 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>


Reviewed-by: Alexey Klimov <alexey.klimov@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
>