From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966763AbbLPRlA (ORCPT ); Wed, 16 Dec 2015 12:41:00 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:50044 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966621AbbLPRko (ORCPT ); Wed, 16 Dec 2015 12:40:44 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mirza Krak , Marc Kleine-Budde , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 095/128] can: sja1000: clear interrupts on start Date: Wed, 16 Dec 2015 09:38:55 -0800 Message-Id: <1450287568-19808-96-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1450287568-19808-1-git-send-email-kamal@canonical.com> References: <1450287568-19808-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt12 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mirza Krak 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: Kamal Mostafa --- 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 32bd7f4..0c048e2 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); } -- 1.9.1