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authorWolfgang Grandegger <wg@grandegger.com>2016-06-13 16:44:19 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2016-06-20 10:32:40 +0300
commit43200a4480cbbe660309621817f54cbb93907108 (patch)
tree1334834bf844d7544a169d25ccef8c4cc21d4bb5
parent427460c83cdf55069eee49799a0caef7dde8df69 (diff)
downloadlinux-43200a4480cbbe660309621817f54cbb93907108.tar.xz
can: at91_can: RX queue could get stuck at high bus load
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> Cc: <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
-rw-r--r--drivers/net/can/at91_can.c5
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;