Received: by 2002:a25:7ec1:0:0:0:0:0 with SMTP id z184csp2280371ybc; Sun, 24 Nov 2019 17:26:07 -0800 (PST) X-Google-Smtp-Source: APXvYqzNHSsMHhFJjpKOneVVFvXHfnBXQwNZm6BzB3/DwhJaBGOqqgcBJg2y/xM8vIFNygrYuc0R X-Received: by 2002:a17:906:5fd0:: with SMTP id k16mr34236337ejv.243.1574645167013; Sun, 24 Nov 2019 17:26:07 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1574645167; cv=none; d=google.com; s=arc-20160816; b=NhF793tFwTCYz7rKgYx4ubuVtLJdaHNy2fhWGaXDnHEIxeUbC4a0mHpGX5aCXvZ2w9 Jj5DYJuvrEeCYaRXyaEVq2KI/Be7f68rBRwSRND4vu6k3pqbfhGaaKD3TvQlYeknE1Zc V8vBmU1gmsIKIFCg+Z7+BdHw5HpNqPv18KrQzutK/fLv7xE6qwrI8Z5v/LXPh9F/Kjnt bUNuUEdII/u/DAtOpn94+GhdrZp9p53GQ3+Xu1cWxlRkfHjfgYpmLbnpkeN/8GGAf++6 tEyt3PL55/mPsElrdprQgo/unGeomnE2FtQIcpZ5w+OlOVUhFZ45k6GDtNEQr9ALCTBD vb3g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=YyJ1VR1edEPFGr7f1Rvpj3bxfKGaJt/XzYaaditupjE=; b=muEcFE5BcTnaI3+BRIj+o6lO/+tX8I9aNsaFL2pggTnstT3VyqsvfrabJhT4zV68w0 ClmKtcUPso0U4uOOvIlykOFNwAJ/r8GNcyEIzDSqupIwRcwtuBqG+scUSLh3o79fr5Bv bQ8OK1imy8pXUdoGEdfI2QWp2WQNX8BrAGGzbDHz0i0ant9f8wdzm6UK91/XFLrFFEOR C/DD/aRWqlydX2y4EibSR1J4iEwlfdmmcr1zV9kDmUiObKV17c6q3UfmToofCDonHDTM tv5kInPfPeHpD2MjR7RCONwR2VJzsQ2jz+hAA3+Z+wc3QVQpVJr/kmtnfesTuMBkAzZT vciA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=L0CMZZSN; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g12si3549060ejd.43.2019.11.24.17.25.41; Sun, 24 Nov 2019 17:26:06 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=L0CMZZSN; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727240AbfKYBV2 (ORCPT + 99 others); Sun, 24 Nov 2019 20:21:28 -0500 Received: from mail-yw1-f68.google.com ([209.85.161.68]:39591 "EHLO mail-yw1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727127AbfKYBV2 (ORCPT ); Sun, 24 Nov 2019 20:21:28 -0500 Received: by mail-yw1-f68.google.com with SMTP id d80so4855878ywa.6 for ; Sun, 24 Nov 2019 17:21:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=YyJ1VR1edEPFGr7f1Rvpj3bxfKGaJt/XzYaaditupjE=; b=L0CMZZSNKy4EC3zHjWVVtEtzScdrqbEarwGtYrD/wzZo43TPeKPLRknHDO888u07nK FB4NbaSETotNJ+pm4ifFjJXL57SrVCkuVSA+0jO5JW1mJLviGDl3ZlABZ8QaA/kc6J67 gV0jXe230C3aVGgC4YaXQbBViQ1VsHUMWBSHPpC9z22yqyvZaV/IgsstM8v0XlCYjMnl 7wh89Xxh3UL+vkN9qdtKwI9sPSlpWIy2arSQiZNuqG69QB3Ej0j9Wx+hLtLSr9Hz4Kw3 qH6CBVskxyjAMfHspXnhdW5NMov9oJZnrDqJd2PDUAqS8a+JAhYsyW4CSq8G462jIZYu S2dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=YyJ1VR1edEPFGr7f1Rvpj3bxfKGaJt/XzYaaditupjE=; b=lcs9zVMiCTz1Vd1Gm4X/GzdHqp8yr36ZP8JBmV2OepmkytNI3Yt9db6okh1ZwNLQSx yI4zeQcWb9JRDyo6pnxAq16dP/kd1Bv/zswLeAug4OT64PnccKMSBivz/C83+uIFKG2e mnPbSMuJl5+vyaq94tNmsiGaEAZWHF00EZ9axy+CWWR6n+41XS6qOwde3Q2LkjunxmfH BR0aBfWZzTwrJR1PLHyHTXhzXwlmN4lqnYccEqzus6f9gudP7w/kEqoej0LZa+rALqWv tTaftqB2mssOawWMPrVXDvaEyRTw3IIa0OuQatlvhBK+mS11F18K7teE3cpqRhu/+U78 oqXA== X-Gm-Message-State: APjAAAXGbF/EXcI2L4ixj5jpkTSZikQsrbk/fHVWi6h2ZvCUO+wKcUB5 3UcL5yRmZxHXvA06vy4X4OouhA== X-Received: by 2002:a81:53c2:: with SMTP id h185mr18749895ywb.113.1574644887312; Sun, 24 Nov 2019 17:21:27 -0800 (PST) Received: from leoy-ThinkPad-X240s (li2093-158.members.linode.com. [172.105.159.158]) by smtp.gmail.com with ESMTPSA id y77sm2893809ywg.75.2019.11.24.17.21.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 24 Nov 2019 17:21:26 -0800 (PST) Date: Mon, 25 Nov 2019 09:21:19 +0800 From: Leo Yan To: Jeffrey Hugo Cc: Andy Gross , Greg Kroah-Hartman , Jiri Slaby , Bjorn Andersson , Stephen Boyd , Nicolas Dechesne , MSM , linux-serial@vger.kernel.org, lkml Subject: Re: [PATCH 1/2] tty: serial: msm_serial: Fix lockup for sysrq and oops Message-ID: <20191125012119.GA15822@leoy-ThinkPad-X240s> References: <20191124154334.15366-1-leo.yan@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jeffrey, On Sun, Nov 24, 2019 at 04:00:21PM -0700, Jeffrey Hugo wrote: > On Sun, Nov 24, 2019 at 8:44 AM Leo Yan wrote: > > > > As the commit 677fe555cbfb ("serial: imx: Fix recursive locking bug") > > has mentioned the uart driver might cause recursive locking between > > normal printing and the kernel debugging facilities (e.g. sysrq and > > oops). In the commit it gave out suggestion for fixing recursive > > locking issue: "The solution is to avoid locking in the sysrq case > > and trylock in the oops_in_progress case." > > > > This patch follows the suggestion (also used the exactly same code with > > other serial drivers, e.g. amba-pl011.c) to fix the recursive locking > > issue, this can avoid stuck caused by deadlock and print out log for > > sysrq and oops. > > > > Signed-off-by: Leo Yan > > Shouldn't this patch have a Fixes tag? Will add fixes tag in next spin. > Was there a cover letter? Okay, I will add cover letter for patch set v2. Thanks for reviewing! Leo