On 2021-11-05 at 18:14, Mark Copper wrote:
> Where to start diagnosing a problem like this?
At first blush: look into ways to disable kernel modesetting.
The details tend to vary depending on the GPU involved, but one thing
they usually have in common is adding 'nomodeset' to the kernel command
line.
I think I usually see the changeover to KMS happening later than the
point right after "loading initial ramdisk", but there's no guarantee
that that will always be the case, and the symptom seems right.
> Minimal install -- no desktop.
>
> No "oops" in syslog though there are some warnings.
>
> System seems to shut down properly when power button pressed.
> Yesterday I could even ssh in, but that facility disappeared.
Shut down immediately (hard-power-off style, much like you get when
pressing that button during POST), or initiate shutdown and complete
after the normal amount of shutdown time (as you get when initiating a
shutdown command from the software UI within the booted OS)?
The answer should help us tell how far it had managed to boot before the
power-button press happened.
> Asrock H570M-ITX/ac with Intel i3-10100. More info gladly provided.
There's a specific kernel-command-line parameter (on top of 'nomodeset')
for disabling KMS with certain types of Intel integrated GPU; I don't
remember it off the top of my head, but I believe it involves the string
'i915'. If you're using such a GPU, it might be worth looking into that.
Disabling kernel modesetting isn't the greatest thing for long-term use,
but if it can let you boot, you may be able to use that as a basis for
figuring out what other solutions may be possible.
Regarding longer-term use, I bumped into this discussion this morning which might be helpful: