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>
This commit is contained in:
Wolfgang Grandegger 2016-06-13 15:44:19 +02:00 committed by Marc Kleine-Budde
parent 427460c83c
commit 43200a4480

View File

@ -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;