Does sysrq work over USB?

Valentin Vidić vvidic at valentin-vidic.from.hr
Tue Nov 16 16:29:00 EST 2021


On Tue, Nov 16, 2021 at 03:04:56PM +0100, Marc SCHAEFER wrote:
> First, reading documentation, I thought that this would not be possible with
> USB and only with the internal serial port [1], but then, reading kernel
> source, it looks it should work with my adapter:
> 
>    Oct 11 14:30:56 apu2-init7 kernel: [    9.915105] usb 2-2: pl2303 converter now attached to ttyUSB0
> 
> since the driver [2] contains code for magic sysrq, see line 993 for
> sysrq mode and line 892 for break handling, with implementation in [3]
> (lines 589-597).
> 
> I am running Debian buster kernel 4.19.0-18-amd64 on the apu2.
> 
> Should I abandon all hope to make it work with USB, or should it work?
> 
> Thank your for any pointers.

Do you have console=ttyUSB0,... set? What does /proc/consoles say?

-- 
Valentin



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