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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 65A39ECDE47 for ; Thu, 25 Oct 2018 14:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C05F2083E for ; Thu, 25 Oct 2018 14:36:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="PPtfay5t"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="S8h62TKP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C05F2083E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.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 S1727970AbeJYXJp (ORCPT ); Thu, 25 Oct 2018 19:09:45 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:44948 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727323AbeJYXJo (ORCPT ); Thu, 25 Oct 2018 19:09:44 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 293DD60ADB; Thu, 25 Oct 2018 14:36:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1540478201; bh=ae06Uuix05sxCrgjLdzFa+7st8or6RmpnX5uJM851+Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PPtfay5tb8q67/M171Es/WbzT4jaCYZymWzEhs7JhPLyBdl8DEGUBkj034Vv+wxR+ ANNyl5JUY7Ys983i+yynpFpS36gcDhy4rJZFK8jph3YBG3ahetA1uGWlgaTzDQB7kc RT7IKe6kQOJx1kohU4hcjEyqGyzk+I+DCBxX2lZQ= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 6DE1E60769; Thu, 25 Oct 2018 14:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1540478199; bh=ae06Uuix05sxCrgjLdzFa+7st8or6RmpnX5uJM851+Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=S8h62TKPNMWm2SwmjLZ4dCQDg1xbXP/q+1WcUFzTsW7LeFlyB5RHB4GE/V0hJSzad 8En3nu6yRHv+PpAhHhfjnaIzAlpy2bcuA9SPxqAgj9nI16Zp814KG9kO4xE3/skJQD SGBWqzuDpos2Fz7GTTGdSQ9kJO4q5iRB8mxmivc0= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 25 Oct 2018 20:06:39 +0530 From: saiprakash.ranjan@codeaurora.org To: Steven Rostedt , srinivas.kandagatla@linaro.org, Stephen Boyd Cc: Joel Fernandes , 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 In-Reply-To: <20181019111205.5c8e98e8@gandalf.local.home> 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> <20181019111205.5c8e98e8@gandalf.local.home> Message-ID: <1e6cc1fa5263b9edfcf7567d3f9f65fd@codeaurora.org> X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/19/2018 8:42 PM, Steven Rostedt wrote: > 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. > Hi, Sorry for late response on this, was running out of debug options ;-) Finally after bisecting (which I should have done earlier) this issue till 4.4 kernel where I don't see the crash, I could see that dma node in "apq8016-sbc.dtsi" is somehow causing the crash. dma@7884000 { status = "okay"; <--- This one }; serial@78af000 { label = "LS-UART0"; status = "okay"; pinctrl-names = "default", "sleep"; pinctrl-0 = <&blsp1_uart1_default>; pinctrl-1 = <&blsp1_uart1_sleep>; }; serial@78b0000 { label = "LS-UART1"; status = "okay"; pinctrl-names = "default", "sleep"; pinctrl-0 = <&blsp1_uart2_default>; pinctrl-1 = <&blsp1_uart2_sleep>; }; "If I disable dma node and LS-UART0, then I don't see any crash and ftrace also works fine" And one more observation is that even without ftrace cmdline, if I use earlycon and disable dma, I face the same crash. So basically this seems to be some kind of earlycon and dma issue and not ftrace(I can be wrong). So adding Srinivas for more info on this dma node. Also just for a note: apq8096-db820c.dtsi shows UART0 is disabled because bootloader does not allow access to it. Could this also be the case for db410c? Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation