Hi,
Some details.
I have never seen this issue starting after displaying the BIOS screen
which is graphic with mouse. Then Debian works fine.
Linux Mint Live on a USB key works always fine.
It is the same, after a session of Linux Mint Live, I reboot the machine
then Debian works fine.
I think that the Radeon GPU keeps some settings after the BIOS session
or the Linux Mint session and work fine until a poweroff.
So i think that the module Radeon (or the firmware) has not the good
parameters when it is launched directly by Debian. It is a simple guess.
modeset=0 works fine but with a very bad resolution not usable.
modeset=1 or auto has this bug since some weeks even I launches startx.
This settings has been working well for years with Debian Bullseye.
What's strange is that the mouse doesn't work on the next startup after
the last not wanted reboot. But the next succeeded reboot after a bad,
the mouse works fine. It work as some register does not reset on boot
but a poweroff.
--
Rpnpif
