Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755114AbcCBBzT (ORCPT ); Tue, 1 Mar 2016 20:55:19 -0500 Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:42851 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754735AbcCAXvx (ORCPT ); Tue, 1 Mar 2016 18:51:53 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=mandrill; d=linuxfoundation.org; b=jRTcC5RVN0dOz3fYNJTkA5ubSt1HJ0Da2/c2//gRWtXcRV0/yObQ5sGNQ3oGzsB3Hr+iDqt/rf/R XQfnQAtWaIL+1c5YYOVFY28HdGQpga/QpdLODKLq5AlFnbf1iMK/+nNeJQVYKOhJw6f37GPmZrJS mQtrHOGG5gc1U6jAOT8=; From: Greg Kroah-Hartman Subject: [PATCH 3.14 072/130] can: sja1000: clear interrupts on start X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , Mirza Krak , Christian Magnusson , Marc Kleine-Budde Message-Id: <20160301234502.345390576@linuxfoundation.org> In-Reply-To: <20160301234459.768886030@linuxfoundation.org> References: <20160301234459.768886030@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.b3c19be8f86a4a6392197ced5530d4d2 X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:51:15 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1495 Lines: 45 3.14-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: Greg Kroah-Hartman --- drivers/net/can/sja1000/sja1000.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -187,6 +187,9 @@ static void sja1000_start(struct net_dev /* clear interrupt flags */ priv->read_reg(priv, SJA1000_IR); + /* clear interrupt flags */ + priv->read_reg(priv, SJA1000_IR); + /* leave reset mode */ set_normal_mode(dev); }