Arch Linux

Khaibit

Member

Registered: 2023-04-25

Posts: 2

No display output on 6.2.11-zen or later with AMD RX 6600 GPU

Hello all,

I've encountered an issue with my Arch system after updating the linux-zen kernel package a bit ago. I was hoping it was something that would be fixed in a subsequent release so I waited for 6.2.12-zen but it appears to be occurring here as well. Quick summary:

System is an Intel 8700K CPU, Asus Maximus X motherboard, Gigabyte RX6600 GPU. Using Wayland, KDE Plasma, and SDDM; the first two are updated to latest in the repo as of today, the last is the latest sddm-git. CSM is disabled in UEFI, resizable BAR support enabled.  Displays are two DisplayPort-connected Dell 1440p monitors daisy-chained via DP-MST. Boots fine on 6.1.25-LTS, booted fine on 6.2.9-zen, black screen on 6.2.11-zen and 6.2.12-zen.  This behavior is maintained if I attempt to use X instead of Wayland as well.

I have a boot log from journalctl for each kernel -- would including each in code tags be the appropriate way to attach that info?  From my perusal of them myself, the following two points jump out at me:

• The following two lines are present in the LTS kernel boot that are not present in the Zen kernel boot:

  • kernel: fbcon: amdgpudrmfb (fb0) is primary device

  • kernel: amdgpu 0000:03:00.0: [drm] fb0: amdgpudrmfb frame buffer device

• And when SDDM sets up, on the Zen kernel the following is logged that is not in LTS:

  • sddm-greeter[479]: Creating a fake screen in order for Qt not to crash

Offhand, it looks like something related to the framebuffer not being correctly set up and thus there's nothing to actually display on, but I'm sort of lost on where to go from here. Has anyone else seen this? Thanks!

Edit April 28: On a whim, grabbed the TKG kernel and built it myself after testing with 6.2.13-zen and still getting no video.  To my surprise, the TKG 6.2.13 tree boots just fine and I get video like normal.  Going to see if I can determine what configuration difference between my now-running kernel and the Zen kernel is causing this.

Last edited by Khaibit (2023-04-28 18:19:12)

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 9,003

Website

Re: No display output on 6.2.11-zen or later with AMD RX 6600 GPU

I have a boot log from journalctl for each kernel -- would including each in code tags be the appropriate way to attach that info?

Probably best to use a pastebin site and share the link here if the output is very large. https://wiki.archlinux.org/title/List_o … n_services

black screen on 6.2.11-zen and 6.2.12-zen

So the screen goes black immediately after the bootloader screen? Can you get to a console if SDDM is disabled?

---

Jin, Jîyan, Azadî

Khaibit

Member

Registered: 2023-04-25

Posts: 2

Re: No display output on 6.2.11-zen or later with AMD RX 6600 GPU

I have a boot log from journalctl for each kernel -- would including each in code tags be the appropriate way to attach that info?

Probably best to use a pastebin site and share the link here if the output is very large. https://wiki.archlinux.org/title/List_o … n_services

Thanks, here's those:

6.2.12-zen boot + attempt to reboot: https://pastebin.com/fVAL6d9v
6.1.25-LTS successful boot: https://pastebin.com/jJifRG4K

black screen on 6.2.11-zen and 6.2.12-zen

So the screen goes black immediately after the bootloader screen? Can you get to a console if SDDM is disabled?

This is correct -- on 6.2.11-zen and later the displays enter power saving mode after bootloader and never re-wake.  This behavior is consistent if SDDM is disabled, I cannot reach a console either.  Interestingly, I cannot cleanly reboot in this state either -- I can SSH into the machine and execute a "sudo shutdown -r now" but it never actually completes, just gets far enough to disconnect me.  On 6.1.25-LTS I reach the console login as expected.

Thanks again for any insights or suggestions for further testing you may have!