Re: No console anymore. How to figure this out.

Hello, Dale.

On Sat, Mar 21, 2026 at 16:48:52 -0500, Dale wrote:

[ .... ]

> Howdy,

> I did my updates.  Lots of smaller KDE packages this weekend. Anyway, I 
> rebooted and still no console.  No errors in dmesg or messages either 
> except for below.  I'm not sure if it matters.  I see a reply from Aho 
> with a kernel command line to try.  Aho says he had the same issue due 
> to Nvidia changing the drivers somehow.  As I mentioned before, most 
> people likely don't use a console anymore. They may not even know how to 
> get to it.  I'm going to add that and try it.  If it works, we'll talk 
> about what that disables and if it will affect anything else or be 
> phased out as a option in the future.  I need my console.  I don't like 
> rebooting all the time.

> What I found in dmesg.

> [   13.725016] nvidia: loading out-of-tree module taints kernel.
> [   13.725023] nvidia: module license 'NVIDIA' taints kernel.
> [   13.725025] Disabling lock debugging due to kernel taint
> [   13.725027] nvidia: module license taints kernel.
> [   14.061410] nvidia-nvlink: Nvlink Core is being initialized, major 
> device number 242

> [   14.064603] nvidia 0000:09:00.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=none:owns=none
> [   14.304388] NVRM: loading NVIDIA UNIX x86_64 Kernel Module 580.142 Tue Mar  3 20:04:04 UTC 2026
> [   14.323357] nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms  580.142  Tue Mar  3 18:59:57 UTC 2026
> [   14.325218] [drm] [nvidia-drm] [GPU ID 0x00000900] Loading driver
> [   15.909018] [drm] Initialized nvidia-drm 0.0.0 for 0000:09:00.0 on minor 0
> [   15.909071] Console: switching to colour dummy device 80x25
> [   15.909103] nvidia 0000:09:00.0: vgaarb: deactivate vga console

> Last line makes me wonder.  :/

The second last line "switching to colour dummy device 80x25" looks like
an error.  The dummy console is only meant to be a workaround at early
boot time to provide an interface for messages being written "to the
screen" before the screen is initialised.  What I have in my dmesg at
the same position is:

[    1.100292] Console: switching to colour frame buffer device 240x67

Do you also have an earlier "switching to colour dummy device 80x25" in
dmesg?  If so, the second one will be indicating that the nvidia-drivers
console which has just been initialised doesn't satisfy some requirement,
so the fallback is to switch back to the dummy console.

The last line:

> [   15.909103] nvidia 0000:09:00.0: vgaarb: deactivate vga console

is likely the console driver cleaning itself up after the failed
initialisation.

> Off to prep another try.

Surely J.O. Aho's suggestion about setting parameters in the kernel
command line has got to be the next step?

> Thanks.

> Dale

> :-)  :-)

-- 
Alan Mackenzie (Nuremberg, Germany).