From 5c3a7aac3d8dc9baa708c7ce37df2dbae3098d1d Mon Sep 17 00:00:00 2001 From: Wolfgang Grandegger Date: Mon, 13 Jun 2016 15:44:19 +0200 Subject: [PATCH] can: at91_can: RX queue could get stuck at high bus load commit 43200a4480cbbe660309621817f54cbb93907108 upstream. At high bus load it could happen that "at91_poll()" enters with all RX message boxes filled up. If then at the end the "quota" is exceeded as well, "rx_next" will not be reset to the first RX mailbox and hence the interrupts remain disabled. Signed-off-by: Wolfgang Grandegger Tested-by: Amr Bekhit Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/at91_can.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c index 6efe27458116c..8e2d394628ed2 100644 --- a/drivers/net/can/at91_can.c +++ b/drivers/net/can/at91_can.c @@ -730,9 +730,10 @@ static int at91_poll_rx(struct net_device *dev, int quota) /* upper group completed, look again in lower */ if (priv->rx_next > get_mb_rx_low_last(priv) && - quota > 0 && mb > get_mb_rx_last(priv)) { + mb > get_mb_rx_last(priv)) { priv->rx_next = get_mb_rx_first(priv); - goto again; + if (quota > 0) + goto again; } return received;