From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:41470 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752018AbcAEPaW (ORCPT ); Tue, 5 Jan 2016 10:30:22 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: Mirza Krak , Marc Kleine-Budde , Jiri Slaby Subject: [patch added to the 3.12 stable tree] can: sja1000: clear interrupts on start Date: Tue, 5 Jan 2016 16:28:37 +0100 Message-Id: <1452007726-3747-36-git-send-email-jslaby@suse.cz> In-Reply-To: <1452007726-3747-1-git-send-email-jslaby@suse.cz> References: <1452007726-3747-1-git-send-email-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Mirza Krak This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 7cecd9ab80f43972c056dc068338f7bcc407b71c upstream. According to SJA1000 data sheet error-warning (EI) interrupt is not cleared by setting the controller in to reset-mode. Then if we have the following case: - system is suspended (echo mem > /sys/power/state) and SJA1000 is left in operating state - A bus error condition occurs which activates EI interrupt, system is still suspended which means EI interrupt will be not be handled nor cleared. If the above two events occur, on resume there is no way to return the SJA1000 to operating state, except to cycle power to it. By simply reading the IR register on start we will clear any previous conditions that could be present. Signed-off-by: Mirza Krak Reported-by: Christian Magnusson Signed-off-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby --- drivers/net/can/sja1000/sja1000.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index f17c3018b7c7..c2d0559115d3 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -184,6 +184,9 @@ static void sja1000_start(struct net_device *dev) priv->write_reg(priv, SJA1000_RXERR, 0x0); priv->read_reg(priv, SJA1000_ECC); + /* clear interrupt flags */ + priv->read_reg(priv, SJA1000_IR); + /* leave reset mode */ set_normal_mode(dev); } -- 2.6.4