Messages in this thread | | | Subject | Re: Crash in msm serial on dragonboard with ftrace bootargs | From | Sai Prakash Ranjan <> | Date | Wed, 17 Oct 2018 16:57:42 +0530 |
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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 <saiprakash.ranjan@codeaurora.org> wrote: >>> >>>> On 10/17/2018 12:33 AM, Steven Rostedt wrote: >>>>> On Wed, 17 Oct 2018 00:31:03 +0530 >>>>> Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> 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.
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