From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755773AbcHSHYv (ORCPT ); Fri, 19 Aug 2016 03:24:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:49739 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755445AbcHSHL7 (ORCPT ); Fri, 19 Aug 2016 03:11:59 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Wolfgang Grandegger , Marc Kleine-Budde , Jiri Slaby Subject: [PATCH 3.12 041/100] can: at91_can: RX queue could get stuck at high bus load Date: Fri, 19 Aug 2016 09:10:40 +0200 Message-Id: <79391f047fcc46a0677db20a82b015ffee64c8ce.1471589700.git.jslaby@suse.cz> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wolfgang Grandegger 3.12-stable review patch. If anyone has any objections, please let me 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