Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753216AbbKJN7m (ORCPT ); Tue, 10 Nov 2015 08:59:42 -0500 Received: from mail-lb0-f176.google.com ([209.85.217.176]:36278 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752976AbbKJN7k (ORCPT ); Tue, 10 Nov 2015 08:59:40 -0500 From: Mirza Krak X-Google-Original-From: Mirza Krak < mirza.krak@hostmobility.com > To: wg@grandegger.com, mkl@pengutronix.de Cc: andri.yngvason@marel.com, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Mirza Krak Subject: [PATCH 1/1] can: sja1000: clear interrupts on start Date: Tue, 10 Nov 2015 14:59:34 +0100 Message-Id: <1447163974-24514-1-git-send-email-mirza.krak@hostmobility.com> X-Mailer: git-send-email 2.1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1549 Lines: 45 From: Mirza Krak 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 --- 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 7b92e911a616..f10834be48a5 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -218,6 +218,9 @@ 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); } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/