loeriver Posted 23 hours ago Posted 23 hours ago From time to time I see a message like this in my log files: 2025-06-05T11:29:33.367636+02:00 bananapipro2 kernel: [934985.549250] 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) show-blocked-tasks(w) dump-ftrace-buffer(z) replay-kernel-logs(R) The system continues to work (although I remember that it stooped at this point in older releases). Is there any action required? I am afraid that this could stop my system which is running unattended for longer periods usually. I am running v25.2.2 for Banana Pi Pro running Armbian Linux 6.12.20-current-sunxi. 0 Quote
IBV Posted 15 hours ago Posted 15 hours ago Hi, it looks like you or a process is triggering the SysRq key. For example, If I press Alt + PrtSc (SysRq) + h, I see the same message in dmesg. https://en.wikipedia.org/wiki/Magic_SysRq_key 0 Quote
djurny Posted 13 hours ago Posted 13 hours ago Hi @loeriver, Check your serial console, as sending a serial <BRK> will trigger the Magic Sysrq sequence. For example, using `tio` to connect to a serial console, I can invoke the Magic Sysrq help test with <ctrl>-t + B + <enter>. Perhaps your serial port has it's RX line shorted to ground? Groetjes, 0 Quote
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