Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754989AbcJLMvE (ORCPT ); Wed, 12 Oct 2016 08:51:04 -0400 Received: from mail.kernel.org ([198.145.29.136]:49372 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755298AbcJLMqm (ORCPT ); Wed, 12 Oct 2016 08:46:42 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Mirza Krak , Marc Kleine-Budde , Zefan Li Subject: [PATCH 3.4 053/125] can: sja1000: clear interrupts on start Date: Wed, 12 Oct 2016 20:32:49 +0800 Message-Id: <1476275641-4697-53-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1476275600-4626-1-git-send-email-lizf@kernel.org> References: <1476275600-4626-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1658 Lines: 50 From: Mirza Krak 3.4.113-rc1 review patch. If anyone has any objections, please let me 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 [lizf: Backported to 3.4: s/SJA1000_IR/REG_IR/] Signed-off-by: Zefan Li --- 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 2d3ad72..1824486 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -177,6 +177,9 @@ static void sja1000_start(struct net_device *dev) priv->write_reg(priv, REG_RXERR, 0x0); priv->read_reg(priv, REG_ECC); + /* clear interrupt flags */ + priv->read_reg(priv, REG_IR); + /* leave reset mode */ set_normal_mode(dev); } -- 1.9.1