[SRU][G/raspi][PATCH] UBUNTU: SAUCE: Revert "mailbox: avoid timer start from callback"

[Juerg Haefliger]

BugLink: https://bugs.launchpad.net/bugs/1907432

This reverts commit 186734a27698abec8f1dec2adb819ceccebf2ffc to fix
a shutdown issue on the Pi 400.

See: https://github.com/raspberrypi/linux/issues/3941

Signed-off-by: Juerg Haefliger <juergh at canonical.com>
---
 drivers/mailbox/mailbox.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 3e7d4b20ab34..0b821a5b2db8 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -82,12 +82,9 @@ static void msg_submit(struct mbox_chan *chan)
 exit:
 	spin_unlock_irqrestore(&chan->lock, flags);
 
-	/* kick start the timer immediately to avoid delays */
-	if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {
-		/* but only if not already active */
-		if (!hrtimer_active(&chan->mbox->poll_hrt))
-			hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);
-	}
+	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);
 }
 
 static void tx_tick(struct mbox_chan *chan, int r)
@@ -125,10 +122,11 @@ static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer)
 		struct mbox_chan *chan = &mbox->chans[i];
 
 		if (chan->active_req && chan->cl) {
-			resched = true;
 			txdone = chan->mbox->ops->last_tx_done(chan);
 			if (txdone)
 				tx_tick(chan, 0);
+			else
+				resched = true;
 		}
 	}
 
-- 
2.25.1