Aaron, > Subject: Debugging reboot freeze > > Hi, > > we are encountering reboot freezes on the current 5.4.66-rt38 kernel with > PREEMPT_RT enabled on i.mx8mm hardware. Where do you get the kernel source code and which version? NXP release or Linux kernel upstream? Also ATF/U-Boot version? > Unfortunately, debugging is difficult in this situation as the only related output > we get during reboot (via serial console) is: > > Rebooting... > Segmentation fault Do you have a debugger to see where it hangs? > > However, the second line is not shown on every reboot; the freeze happens > everytime. > > We already tried various kernel command line options > (print-fatal-signals=1 oops=panic), earlyprintk/earlycon and a lot of debug > printk's in the kernel source. > However it seems that there is no output after > `kernel_restart_prepare(cmd);` in kernel/reboot.c. > > When using the same kernel version without PREEMPT_RT, the issue does not > occur. > > Do you have any hints for further debugging? If you point me your version, and source, I could give a try in my side. Regards, Peng. > Thank you very much in advance. > > Regards, > Aaron Marcher
