diff options
authorWolfgang Grandegger <wg@grandegger.com>2016-06-13 15:44:19 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-10 11:49:28 +0200
commit63b9e0f32f72892de7064c6888484b881ddbb42f (patch)
parentb4fedbef96b8d29f336d355d2b0858518e405090 (diff)
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 <wg@grandegger.com> Tested-by: Amr Bekhit <amrbekhit@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 8b3275d7792a..8f5e93cb7975 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -712,9 +712,10 @@ 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;