| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 52/68] can: at91_can: RX queue could get stuck at high bus load | Date | Mon, 8 Aug 2016 21:11:27 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Wolfgang Grandegger <wg@grandegger.com>
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>
--- drivers/net/can/at91_can.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- 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_devic /* 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;
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