Commit 43200a44 authored Jun 13, 2016 by Wolfgang Grandegger Committed by Marc Kleine-Budde Jun 20, 2016

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>

parent 427460c8

drivers/net/can/at91_can.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -712,8 +712,9 @@ 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);
		if (quota > 0)
		goto again;
		}