Messages in this thread Patch in this message | | | Date | Mon, 20 Mar 2017 18:47:14 +0000 | From | Alexey Klimov <> | Subject | Re: [PATCH] mailbox: always wait in mbox_send_message for blocking tx mode |
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Hi Sudeep,
thanks for sending this patch.
On Mon, Mar 20, 2017 at 03:40:10PM +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 making use of non-negative token returned > by add_to_rbuf to check if the request was queued and block always if > so in blocking Tx 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(-) > > diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c > index 4671f8a12872..d5895791ab5d 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 && t >= 0) {
What do you think about removing t>=0 at all? If add_to_rbuf() above returns negative number then we won't reach this point in code at all and quit this function with error. If execution reaches this line then we can say that t is definetely >= 0 and maybe it shouldn't be checked.
Best regards, Alexey
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