From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2130CC432C0 for ; Mon, 25 Nov 2019 01:21:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8C872071A for ; Mon, 25 Nov 2019 01:21:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="L0CMZZSN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727234AbfKYBV2 (ORCPT ); Sun, 24 Nov 2019 20:21:28 -0500 Received: from mail-yw1-f67.google.com ([209.85.161.67]:38735 "EHLO mail-yw1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727072AbfKYBV2 (ORCPT ); Sun, 24 Nov 2019 20:21:28 -0500 Received: by mail-yw1-f67.google.com with SMTP id m196so4858450ywd.5 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=nq6pz779cX4nxd2996y4z4D2Fj3jX5ORWi8EwY2biehHgHR7lGgc/4Ojzsp3mU5A/I ADkAn4mtUkXH7Cn6VaZEpbfrWFhIh1FaDDejiCp3dps4IL6OvUeZ39QFwM7bm6oDnWKu ARnxvuqoIIZmU9rIST7uSfuhU15pv04DpastcZUXyYoVDmFw7F3+/q/DLYT982n0w/Lx VkW2DeZ0GNlP3dadbg/8QdY1I4fcq+Avkgnl7jfxLU5hntcHJy9k6q/kps18XYTlfrZH 9/iMYmIE+lulVjLdv+GI19wn8DLEUuz5ssCRdFUDjawdwcB9HKNby269mCBE9O/hkm0e UGKQ== X-Gm-Message-State: APjAAAVWsHC8A0HUPEqEdTsOiGi1OEBn3+bq2B54Vmtl1t4b6dsTirzS qv8U4KtwK1UTd/cMOOCPbh25Ig== X-Google-Smtp-Source: APXvYqzvTeM7VZxhefQxQflut8iI1Dd7/df/CtPUfTacT0Piue1SPIhfmuYsOuOmjX2cP9jsVuNdKg== 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-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@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