On Fri, 19 Oct 2018 20:18:19 +0530 Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx> 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
