Merge "drivers: mailbox: fix race resulting in multiple message submission" (b45d92fd) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/mailbox/mailbox.c

+19 −1

Original line number	Diff line number	Diff line
		@@ -53,7 +53,7 @@ static int add_to_rbuf(struct mbox_chan chan, void mssg)
		return idx;
		}

		static void msg_submit(struct mbox_chan *chan)
		static int __msg_submit(struct mbox_chan *chan)
		{
		unsigned count, idx;
		unsigned long flags;
		@@ -85,6 +85,24 @@ static void msg_submit(struct mbox_chan *chan)
		exit:
		spin_unlock_irqrestore(&chan->lock, flags);

		return err;
		}

		static void msg_submit(struct mbox_chan *chan)
		{
		int err = 0;

		/*
		* If the controller returns -EAGAIN, then it means, our spinlock
		* here is preventing the controller from receiving its interrupt,
		* that would help clear the controller channels that are currently
		* blocked waiting on the interrupt response.
		* Retry again.
		*/
		do {
		err = __msg_submit(chan);
		} while (err == -EAGAIN);

		if (!err && (chan->txdone_method & TXDONE_BY_POLL))
		/* kick start the timer immediately to avoid delays */
		hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);