From patchwork Wed Sep 13 17:42:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 813550 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xsprw0lHgz9sNV for ; Thu, 14 Sep 2017 03:42:24 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751421AbdIMRmQ (ORCPT ); Wed, 13 Sep 2017 13:42:16 -0400 Received: from andre.telenet-ops.be ([195.130.132.53]:52528 "EHLO andre.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117AbdIMRmO (ORCPT ); Wed, 13 Sep 2017 13:42:14 -0400 Received: from ayla.of.borg ([84.195.106.246]) by andre.telenet-ops.be with bizsmtp id 95iC1w0095JzmfG015iCl0; Wed, 13 Sep 2017 19:42:13 +0200 Received: from ramsan.of.borg ([192.168.97.29] helo=ramsan) by ayla.of.borg with esmtp (Exim 4.86_2) (envelope-from ) id 1dsBfs-00047w-7o; Wed, 13 Sep 2017 19:42:08 +0200 Received: from geert by ramsan with local (Exim 4.86_2) (envelope-from ) id 1dsBfw-0002bz-C8; Wed, 13 Sep 2017 19:42:12 +0200 From: Geert Uytterhoeven To: "David S . Miller" , Steve Glendinning Cc: Andrew Lunn , Florian Fainelli , netdev@vger.kernel.org, linux-pm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2] net: smsc911x: Quieten netif during suspend Date: Wed, 13 Sep 2017 19:42:05 +0200 Message-Id: <1505324525-9998-1-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 2.7.4 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If the network interface is kept running during suspend, the net core may call net_device_ops.ndo_start_xmit() while the Ethernet device is still suspended, which may lead to a system crash. E.g. on sh73a0/kzm9g and r8a73a4/ape6evm, the external Ethernet chip is driven by a PM controlled clock. If the Ethernet registers are accessed while the clock is not running, the system will crash with an imprecise external abort. As this is a race condition with a small time window, it is not so easy to trigger at will. Using pm_test may increase your chances: # echo 0 > /sys/module/printk/parameters/console_suspend # echo platform > /sys/power/pm_test # echo mem > /sys/power/state To fix this, make sure the network interface is quietened during suspend. Signed-off-by: Geert Uytterhoeven Reviewed-by: Florian Fainelli --- This is v2 of the series "[PATCH 0/2] net: Fix crashes due to activity during suspend", which degenerated into a single patch after commit ebc8254aeae34226 ("Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()"") made "[PATCH 1/2] net: phy: Freeze PHY polling before suspending devices" no longer needed. v2: - Spelling s/quit/quiet/g. No stacktrace is provided, as the imprecise external abort is usually reported from an innocent looking and unrelated function like __loop_delay(), cpu_idle_poll(), or arch_timer_read_counter_long(). --- drivers/net/ethernet/smsc/smsc911x.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c index 0b6a39b003a4e188..012fb66eed8dd618 100644 --- a/drivers/net/ethernet/smsc/smsc911x.c +++ b/drivers/net/ethernet/smsc/smsc911x.c @@ -2595,6 +2595,11 @@ static int smsc911x_suspend(struct device *dev) struct net_device *ndev = dev_get_drvdata(dev); struct smsc911x_data *pdata = netdev_priv(ndev); + if (netif_running(ndev)) { + netif_stop_queue(ndev); + netif_device_detach(ndev); + } + /* enable wake on LAN, energy detection and the external PME * signal. */ smsc911x_reg_write(pdata, PMT_CTRL, @@ -2628,7 +2633,15 @@ static int smsc911x_resume(struct device *dev) while (!(smsc911x_reg_read(pdata, PMT_CTRL) & PMT_CTRL_READY_) && --to) udelay(1000); - return (to == 0) ? -EIO : 0; + if (to == 0) + return -EIO; + + if (netif_running(ndev)) { + netif_device_attach(ndev); + netif_start_queue(ndev); + } + + return 0; } static const struct dev_pm_ops smsc911x_pm_ops = {