AMD GPU and NVIDIA RTX 2060 together in a Notebook problems

ingo.kubbilun · March 25, 2020, 3:34pm

Dear all,
just bought an ASUS TUF Gaming Notebook with an AMD Ryzen 3750h (integrated GPU) and an RTX 2060 (6GB).
Got, compiled and got running latest linux 5.6-RC7 with current NVIDIA 440.64 driver (patched to make it compilable).
X11 only runs with integrated AMD GPU (PCI:5:0:0). The NVIDA (PCI:1:0:0) kernel drivers get loaded without problems but no X11 configuration can make this thing working.
I am always getting the “no displays usable” message stuff in Xorg.log.0.
No bumblebee on the system. I do not want both GPUs working simultanously - only the NVIDIA GPU.
It there any chance to get this working???
I tried everything from “blacklist amdgpu”, over modesetting tweaks, etc. Nothing.
I am not a hardware guy but I guess that the laptop screen is wired to the amdgpu and the nvidia driver is unable to take it over.
Why is the X11 stuff always such a configuration war?

generix · March 25, 2020, 7:57pm

It’s possible, in contrast to an intel/nvidia combo it doesn’t get autoconfigured by distros. Which distribution are you using?

ingo.kubbilun · March 26, 2020, 11:01pm

I am using plain Debian 10 (Buster) 64bit. When using NVIDIA GPU, the mode seems to be set but I only see a blank screen.
In Xorg.log.0, I can see:
[ 81.902] (–) NVIDIA(GPU-0): DFP-0: 165.0 MHz maximum pixel clock
[ 81.902] (–) NVIDIA(GPU-0):
[ 81.902] (==) NVIDIA(0):
[ 81.902] (==) NVIDIA(0): No modes were requested; the default mode “nvidia-auto-select”
[ 81.902] (==) NVIDIA(0): will be used as the requested mode.
[ 81.902] (==) NVIDIA(0):
[ 81.902] (–) NVIDIA(0): No enabled display devices found; starting anyway because
[ 81.902] (–) NVIDIA(0): AllowEmptyInitialConfiguration is enabled
[ 81.903] (II) NVIDIA(0): Validated MetaModes:
[ 81.903] (II) NVIDIA(0): “NULL”
[ 81.903] (II) NVIDIA(0): Virtual screen size determined to be 640 x 480
[ 81.903] (WW) NVIDIA(0): Unable to get display device for DPI computation.
[ 81.903] (==) NVIDIA(0): DPI set to (75, 75); computed from built-in default
[ 81.903] (II) NVIDIA: Using 24576.00 MB of virtual memory for indirect memory
[ 81.903] (II) NVIDIA: access.
[ 81.952] (II) NVIDIA(0): Setting mode “NULL”
[ 81.964] (==) NVIDIA(0): Disabling shared memory pixmaps
[ 81.964] (==) NVIDIA(0): Backing store enabled
[ 81.964] (==) NVIDIA(0): Silken mouse enabled
[ 81.964] (**) NVIDIA(0): DPMS enabled

So “Setting mode “NULL”” might be the problem?
My xorg.conf looks like this (snippet, I have cut the modelines computed by another AMDGPU run of X11):

Section “Device”
Identifier “Device1”
Driver “nvidia”
VendorName “NVIDIA Corporation”
BusID “PCI:1:0:0”
EndSection

Section “Device”
Identifier “Device0”
Driver “amdgpu”
BusID “PCI:5:0:0”
Option “PrimaryGPU” “yes”
EndSection

Section “Screen”
Identifier “Screen0”
Device “Device1”
Monitor “Monitor0”
DefaultDepth 24
Option “AllowEmptyInitialConfiguration” “True”
SubSection “Display”
Depth 24
Modes “1920x1080x59.9”
EndSubSection
EndSection

Because I am using lightdm as the wm, I added in /etc/lightdm/iightdm.conf:

[Seat:*]
display-setup-script=/etc/lightdm/display_setup.sh

And the script contains:

#!/bin/sh
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

That’s everything I found so far. But still not working (only with AMDGPU alone).

Cheers, Ingo.

aplattner · March 27, 2020, 6:18am

Can you please run sudo nvidia-bug-report.sh and attach the resulting nvidia-bug-report.log.gz file to your post?

generix · March 27, 2020, 7:50am

Two changes needed in your xorg.conf:
Replace
Driver “amdgpu”
with
Driver “modesetting”
and remove
Option “PrimaryGPU” “yes”
since you want the nvidia gpu to be primary.

ingo.kubbilun · March 27, 2020, 9:53am

Thanks for the suggestions, I will give it a try after work. Would you recommend to purge the AMDGPU (PCI:5:0:0) entry entirely?

generix · March 27, 2020, 10:06am

No, it’s necessary, it just needs the two changes.

ingo.kubbilun · March 27, 2020, 10:48am

Dude, you are awesome! The “modesetting” did the trick. Works like a rock (I am going to write everything down in a PDF document for other users).
Proof:

Thanks a lot.

ingo.kubbilun · March 27, 2020, 10:55am

Topic solved, see below. Have to configure AMDGPU not with amdgpu driver but with modesetting driver. After that, linux 5.6-RC7 with NVIDIA 440.64 (patched for 5.6-RC7 to make it compilable) works great.
Btw, because I think that more and more AMD Ryzen Notebooks will appear on the market, the Linux kernel 5.6 is a must because the CPU throttles down to 400MHz permanently once overheated. This is fixed in kernel 5.6+ only.
Thank you!

generix · March 27, 2020, 12:47pm

Just for completeness, this also works with the amdgpu driver instead of modesetting, just the xrandr commands have to be adopted to it,
xrandr --setprovideroutputsource modesetting NVIDIA-0
has to become
xrandr --setprovideroutputsource amdgpu-blahblah NVIDIA-0
(use xrandr --listproviders to get the correct name)
or simply
xrandr --setprovideroutputsource 0 1
I just recommend using the modesetting driver for two reasons:

on distros with PRIME infrastructure like Ubuntu this will make prime-select work since it then thinks it’s an intel
depending on amdgpu kernel/DDX versions this sometimes has sideffects like graphical artifacts / dual mouse pointers, etc.