Hello, On Sun, Nov 21, 2021 at 07:07:33PM +0100, Valentin Vidi?? wrote:
I tried and it doesn't work for me either, but the problem is most likely missing CONFIG_USB_SERIAL_CONSOLE=y option in the kernel build:
Yes, with a kernel recompiled with those options and grub configured, I get: CONFIG_USB=y CONFIG_USB_SERIAL=y CONFIG_USB_SERIAL_CONSOLE=y CONFIG_U_SERIAL_CONSOLE=y I get: root@gluster-1:~# cat /proc/consoles tty0 -WU (EC p ) 4:1 ttyUSB0 -W- (E p ) 188:0 and I can then do sysrq from USB: schaefer@acer-1:~$ cu -l ttyUSB0 -s 9600 Connected. ~%break [ 1633.701624] sysrq: HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e) memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystems(j) sak(k) show-backtrace-all-active-cpus(l) show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p) show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u) force-fb(V) show-blocked-tasks(w) dump-ftrace-buffer(z) Thank you for your help: I have now a way to make it work.