From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sai Prakash Ranjan Subject: Re: Crash in msm serial on dragonboard with ftrace bootargs Date: Wed, 17 Oct 2018 16:57:42 +0530 Message-ID: <17116a6b-156e-af2f-c20c-88bea10bfc92@codeaurora.org> References: <1cae8f10-55f5-20ce-9105-30af6f88bd6e@codeaurora.org> <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> <20181016151516.786b16cc@gandalf.local.home> <0b014d85-9988-0bf5-7b72-911dbbcdadfc@codeaurora.org> <153972306834.5275.7510298070540576604@swboyd.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <153972306834.5275.7510298070540576604@swboyd.mtv.corp.google.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd , Steven Rostedt Cc: Bjorn Andersson , Andy Gross , David Brown , Jiri Slaby , Kees Cook , "Joel Fernandes (Google)" , 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 List-Id: linux-arm-msm@vger.kernel.org On 10/17/2018 2:21 AM, Stephen Boyd wrote: > Quoting Sai Prakash Ranjan (2018-10-16 12:35:57) >> On 10/17/2018 12:45 AM, Steven Rostedt wrote: >>> On Wed, 17 Oct 2018 00:36:05 +0530 >>> Sai Prakash Ranjan wrote: >>> >>>> On 10/17/2018 12:33 AM, Steven Rostedt wrote: >>>>> On Wed, 17 Oct 2018 00:31:03 +0530 >>>>> Sai Prakash Ranjan wrote: >>>>> >>>>>> Haa seems like you are right! With "ftrace=function >>>>>> ftrace_filter=msm_read" , I can trigger the crash, but >>>>>> sadly "ftrace_notrace=msm_read" also crashes. >>>>> >>>>> So there's more than one problem area. >>>>> >>>>> What about ftrace_notrace=m* >>>>> >>>>> ? >>>>> >>>> >>>> That too crashes. >>>> >>> >>> Which compiler are you using and can you send me your config. >>> >> Config attached. >> >> Compiler: aarch64-linux-gnu-gcc (Linaro GCC 6.3-2017.02) 6.3.1 20170109 >> >>> I wonder if there's something screwing up with the way ftrace nops are >>> working on this board. >>> >>> A couple things of note, 1) it works fine after boot up. 2) it crashes >>> in the initcall code, so it's not due to ftrace being enabled too early. >>> >>> I'd like to see the full command line as well. I bet if you remove the >>> qcom,msm-uartdm from the command line, and had just ftrace=function, it >>> may also boot fine too. Can you try that? >>> >> >> Kernel command line: root=/dev/disk/by-partlabel/rootfs rw rootwait >> ftrace=function ftrace_notrace=m* earlycon console=ttyMSM0,115200n8 >> >> qcom,msm-uartdm is not in command line, it is the earlycon. So without >> earlycon(bootconsole), board boots fine as we discussed earlier. >> > > Have you tried with earlycon and no ftrace things on the commandline? > > root=/dev/disk/by-partlabel/rootfs rw rootwait earlycon console=ttyMSM0,115200n8 > > If earlycon is causing problems, it sounds like this may be another case > of earlycon uart handing off to the uart driver and that failing because > something gets printed while the uart is transitioning from the earlycon > console to the kernel boot console. I recall the uart would trample on > itself in interesting ways. > Yes I have tried with only earlycon enabled and everything is fine. Issue is reproduced only with ftrace=function cmdline. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation