[Nouveau] Thinkpad P17 gen 2 kernel 6.4 and 6.6 lack of support for nvidia GA104GLM [RTX A5000 Mobile] and missing module firmware

[Linux User #330250]

On 12/02/23 Marc MERLIN wrote:
> Howdy,

Howdy!

> I'm trying a Thnkpad P17 gen2, the last thinkpad that still comes in 17"
> 4K (newer ones are 16" only, so I'm looking for other worthwhile linux
> laptops with 17" or bigger LCD that also does 4K, the alienware I saw
> was 18" but not 4K)
>
> Unfortunately I seem to need the nouveau driver to turn off the nvidia
> chip I don't plan on using (intel graphics is fine for me), and bios
> only allows 'bybrid' or nvidia only)
> On my P73, nouveau never really worked in the 3 years I've had it, but
> it could at least turn off the nvidia chip. On P17gen2 it does not seem
> to be able to do so.

At the moment you'd have to use the proprietary Nvidia driver for
graphics support. But there are, and have been for a long time, ways to
disable the additional dedicated graphics device completely and save
power, which is nice thing on a laptop...

> sauron:~# lspci | grep VGA
> 00:02.0 VGA compatible controller: Intel Corporation Tiger Lake-H GT1 [UHD Graphics] (rev 01)
> 01:00.0 VGA compatible controller: NVIDIA Corporation GA104GLM [RTX A5000 Mobile] (rev a1)

Note the Nvidia card's PCI address is 01:00.0...

> What is the next recommended step?

STEP #1: disable nouveau by blacklisting the module.

There's more than one way to do this:

* Add it to /etc/modprobe.d/<someconfigfilename>.conf
E.g. /etc/modprobe.d/blacklist-nouveau.conf, run in a root shell (if the
file doesn't already exist!):
echo "blacklist nouveau" > /etc/modprobe.d/blacklist-nouveau.conf

* Add a kernel command line parameter: modprobe.blacklist=nouveau
How you do this depends on which Linux (distribution) you're running.
E.g. GRUB's command line may be used, if GRUB /is/ used, or dracut and
so on...

STEP #2: you could power down the PCI device (only after you've disabled
the driver in step #1).

Try it out first by disabling the PCI device you noted above on a
running system (as root!), e.g. like this:

echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/remove

If that works, you'd do something like adding a new udev rule in e.g.
/etc/udev/rules.d/00-remove-nvidia.rules with contents of the sort:
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de",
ATTR{class}=="0x03[0-9]*", ATTR{power/control}="auto", ATTR{remove}="1"

Take a full example from the Arch Wiki:
https://wiki.archlinux.org/title/Hybrid_graphics

Other resouces:
https://github.com/bayasdev/nvidia-gpu-off
https://unix.stackexchange.com/questions/702774/how-to-disable-pcie-device-at-boot

> Thanks,
> Marc

Welcome! Hope this helps, and I also hope it's not too late. I just saw
your posting and thought, better late than never...
Linux User #330250