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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 35958ECDE43 for ; Fri, 19 Oct 2018 15:12:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF34D20869 for ; Fri, 19 Oct 2018 15:12:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF34D20869 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727078AbeJSXSk (ORCPT ); Fri, 19 Oct 2018 19:18:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:52144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbeJSXSj (ORCPT ); Fri, 19 Oct 2018 19:18:39 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F278220869; Fri, 19 Oct 2018 15:12:06 +0000 (UTC) Date: Fri, 19 Oct 2018 11:12:05 -0400 From: Steven Rostedt To: Sai Prakash Ranjan Cc: Joel Fernandes , Stephen Boyd , Bjorn Andersson , Andy Gross , David Brown , Jiri Slaby , Kees Cook , Geliang Tang , Greg Kroah-Hartman , Pramod Gurav , linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Rajendra Nayak , Vivek Gautam , Sibi Sankar Subject: Re: Crash in msm serial on dragonboard with ftrace bootargs Message-ID: <20181019111205.5c8e98e8@gandalf.local.home> In-Reply-To: <9cafe321-87f6-98a3-3bda-c2f7a3d7fc67@codeaurora.org> References: <472db11e-49a6-a1ee-e298-791ee1bbb10b@codeaurora.org> <20181016141610.639b9000@gandalf.local.home> <20181016144123.24c47b38@gandalf.local.home> <7781815e-cba2-9e36-db6d-268298747876@codeaurora.org> <20181016150328.3450d718@gandalf.local.home> <20181017223334.29ca2837@vmware.local.home> <58d2474c-53cd-e6cb-2d25-db38d1a88da6@codeaurora.org> <20181018091706.62310b38@gandalf.local.home> <20181019041740.GB141835@joelaf.mtv.corp.google.com> <8a75f2d5-f1bd-504e-b545-ae2e2f61ca8f@codeaurora.org> <20181019095122.0f1c0946@gandalf.local.home> <9cafe321-87f6-98a3-3bda-c2f7a3d7fc67@codeaurora.org> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Oct 2018 20:18:19 +0530 Sai Prakash Ranjan wrote: > > You said that if you add 'ftrace_filter=msm_read' to the command line, > > it still crashes? > > > > So only tracing that function we have an issue, right? > > > > Tracing msm_read does cause the crash, but that is not the only one > causing the crash because even after "ftrace_notrace=msm_read" the board > crashes which is why I suspect msm earlycon and not ftrace. I'm saying there's a combination of the two. Because when ftrace is not involved, early con doesn't crash. I would focus on why earlycon crashes when only msm_read is traced. That should help narrow down the cause. What we know is: earlycon -> boots ftrace=function -> boots earlycon ftrace=function ftrace_filter=msm_read -> crashes If we remove the "ftrace=function ftrace_filter=msm_read" it boots fine, and I'm assuming that if we just remove earlycon (keeping the ftrace_filter), it also boots too. Thus, ftrace tracing msm_read is causing earlycon to do something that triggers the crash. -- Steve