AMD RX 5700 XT displays at 1024x768 in Debian Bullseye (Testing) despite having installed drivers and firmware.
 

(I apologize if this gets posted multiple times. The website insists I posted it, but when I go to "My Posts" nothing shows up.)

Hello, I have recently built a PC and installed Debian. After a day or two of trying to figure out why I couldn't start Xorg, I managed to get a seemingly functional desktop. At one point, I decided I wanted to use GPU Passthrough for a project of mine. After adjusting some configurations, I rebooted my system only to realize that apparently Debian was using the card I wanted to passthrough while refusing to use the other the entire time.

After about another day or two of fruitless package-swapping and rebooting, I didn't manage to get anywhere new. Currently my desktop seems to be stuck at 1024x768.

Here is my configuration.

Debian Testing (Upgraded from Debian 10 Stable)

CPU : AMD Ryzen 9 3990x

AMD RX 5700XT (This is the card I want to use on my regular desktop.)

AMD RX 590 (This is the card I want to use for passthrough, apparently it was also the one the system tried to use (Which is odd, because I definitely recall putting this NOT in the main PCI-E slot (As specified in the motherboard's manual.) but instead the card I actually wanted to become the primary card.))

I have previously installed drivers and the required nonfree firmware, I may need to reinstall them again if it turns out something didn't register correctly.

The whole Xorg initialization is in its log file, you can drop it into some pastebin site if you want more eyes looking at it.

Here is the contents of Xorg.1.log

Does your lspci show two cards?

Yes

Do you want the output?

The Output
 

03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e1)
0a:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] [1002:731f] (rev c1)

OK, are you following some guide? Like this one?

Linux does what Windon't
 

I previously was.

This one specifically.

https://www.youtube.com/watch?v=3yhwJxWSqXI

This was the last command I did before I stopped following the tutorial.

sudo nano /etc/modprobe.d/vfio_pci.conf
options vfio_pci ids=1002:67df,1002:aaf0

This is kind of uncharted land for me, never attempted to use IOMMU. Anyhow, you could force Xorg to the card you want by specifying the BusID, see here.

Well, I tried it. A bit of research later, I set the config with the Bus ID and boom!


It failed.

X didn't even start, and apparently neither did my display manager (LightDM).

After deleting the config file and rebooting, I can still use X and such (hence why I'm typing this) but unfortunately the xorg config didn't seem to work.

Here is the config I used, in case you were wondering.

Section "Device"
Identifier "AMD"
Driver "amdgpu"
BusId "1002:731f"
EndSection

This is not BusID, it is the PCI ID. This is what BusID looks like, just example. Edit, this is a quote from the page I linked to. How comes you didn't read it?

I actually caught on to that a little bit before you posted and...

I can get into Xorg with the configuration!

Sort of, I'm still stuck in 1024x768, but at least the card itself works.

So where exactly would I go from here?

Alright, what does your most recent Xorg log tell? The one you posted has no problems in it and much higher resolutions are listed. If you run xrandr in a terminal window, what does it show about available resolutions?