Does sysrq work over USB?
schaefer at alphanet.ch
Sun Nov 21 10:47:57 EST 2021
On Tue, Nov 16, 2021 at 10:29:00PM +0100, Valentin Vidi?? wrote:
> Do you have console=ttyUSB0,... set? What does /proc/consoles say?
No, I did not.
Now, I have added on a test machine:
to /etc/default/grub and started upgrade-grub and rebooted.
I had and I still have:
root at gluster-1:~# cat /proc/consoles
tty0 -WU (EC p ) 4:1
However, the command line seems correct and multiple console= are
root at gluster-1:~# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-4.19.0-18-amd64 root=/dev/mapper/vg1-root ro console=ttyUSB0,9600 console=tty0 quiet raid0.default_layout=1
It does not seem to be work for some reason.
Let's try with one ttyUSB console specification only: does not
boot anymore. Does not print anything on ttyUSB0. Had to recover
using a grub kernel command line edition at boot time.
NB: the USB serial port works with cu bidirectionnally once the
system is booted, but %break has no effect.
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