From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:60562 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753968AbcHRMt5 (ORCPT ); Thu, 18 Aug 2016 08:49:57 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: Wolfgang Grandegger , Marc Kleine-Budde , Jiri Slaby Subject: [patch added to 3.12-stable] can: at91_can: RX queue could get stuck at high bus load Date: Thu, 18 Aug 2016 14:49:07 +0200 Message-Id: <20160818124953.31969-2-jslaby@suse.cz> In-Reply-To: <20160818124953.31969-1-jslaby@suse.cz> References: <20160818124953.31969-1-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Wolfgang Grandegger This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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 Tested-by: Amr Bekhit Signed-off-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby --- 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 693d8ffe4653..67e08af13eb0 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; -- 2.9.3