| From | Willy Tarreau <> | Subject | [PATCH 3.10 148/180] can: at91_can: RX queue could get stuck at high bus load | Date | Sun, 21 Aug 2016 17:31:18 +0200 |
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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> Cc: <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Willy Tarreau <w@1wt.eu> --- drivers/net/can/at91_can.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c index 535d5dd..024078c 100644 --- a/drivers/net/can/at91_can.c +++ b/drivers/net/can/at91_can.c @@ -731,9 +731,10 @@ 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; -- 2.8.0.rc2.1.gbe9624a
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