RX 6900 XT Black Screen/ No Output without nomodeset

telebooth · 2021-01-26 22:20:08

I'm posting here after having suffered this issue through Manjaro and then deciding to use Arch instead, hoping that going for a more barebones setup would at least let me boot without "nomodeset". Unfortunately this hasn't been the case. While working with Manjaro, I'd tried doing all of the setup that Phoronix suggested for the 6800 XT (Mesa 20.3+, Kernel 5.9+, etc.) but none of it worked. On the Manjaro forums, I'd tried using the devel versions, building linux-mainline and running that, and I tried using some AUR repos like mesa-git and linux-firmware-git but I'm not sure if they actually worked. Anyways... I'm posting this here on the Arch Linux forum, hoping that somebody can help me actually get all of my firmware and drivers in order. As a jumping off point, here's a pastebin of my journalctl output when "nomodeset" isn't used. Unfortunately, I don't know how to interpret this output very well. http://ix.io/2NqA.

It looks like it recognizes an amdgpu kernel module and then tries to do *something* with it, but then I don't know where or when it's actually failing. The nature of the failure is that my fans stop spinning and every second or so I'll hear what I can only describe as a "click", the monitor will exit power saving mode (to a black screen), and then go right back in. For reference, I've gotten it "running" under Pop!_OS, but it was called it an "llvm pipe" and it didn't really behave like a full GPU, and I didn't bother trying to figure out how to get the driver installed using Pop!_OS, because I really wasn't interested in the distro at all.

Thanks in advance!

loqs · 2021-01-26 23:03:47

Have you tried booting with the kernel parameter amdgpu.dc=0 ? Also what is radeon.pcie_gen2=0 for?

telebooth · 2021-01-26 23:16:26

Thanks for responding!

I read on the AMDGPU wiki article that sometimes having PCIE gen 2 support enabled can cause instability on some motherboards, it was more a of a hail mary at that point. Running with "amdgpu.dc=0" gives this journal output (http://ix.io/2NqR), and the only notable change is that now it enters power save mode and stays there, it doesn't "click" anymore. I've since found that other 6800 XT thread where it seemed like they were running into similar issues (https://bbs.archlinux.org/viewtopic.php?id=260944), but I can't even get my Arch into a CLI without doing "nomodeset", so putting it into text mode by adding "3" to the end of the first "linux /boot/..." line also wouldn't work.

Last edited by telebooth (2021-01-26 23:16:44)

loqs · 2021-01-26 23:32:47

Is the hardware known to issue free? When you tried linux-mainline was the result the same and what version was it?

telebooth · 2021-01-26 23:40:33

When I did linux-mainline the version ended up being 5.11-rc5 IIRC and I ran into the same issues. Considering I've seen very few posts regarding this card and Linux since it's release in December, I don't know if this card is particularly devoid of issues with Linux. I imagine that, even on Arch, that maybe there isn't full firmware support?

I'll try to use linux-mainline again to see if maybe it'll be different on a clean version of Arch.

Last edited by telebooth (2021-01-26 23:41:10)

loqs · 2021-01-26 23:48:12

If you already tried 5.11-rc5 then I would not bother trying it again. You can obtain it from Unofficial_user_repositories#miffe to save building it.

linux-amd-staging-drm-next-git/ packages the most recent git tree for the amdgpu module.

telebooth · 2021-01-27 00:07:11

Nothing stands out to me in the staging branch as explicitly adding support for the GPU, so maybe it just needs some time. Either way, thanks for your help!

loqs · 2021-01-27 00:20:44

I was suggesting the staging branch to see if any of the latest fixes resolved the issue. If it is not fixed in that tree I would suggest reporting the issue upstream as you will have then checked changes targeting 5.11 and 5.12.

telebooth · 2021-01-27 23:11:13

So.... It was my monitor. Apparently the monitor would work up until a driver was installed, at which point it would stop working completely. I figured something was wrong with my hardware when even Windows was giving me the same results (as soon as I installed the drivers). After switching to a new monitor, everything works as expected.I was also able to test the kernel on the amdgpu staging branch, and it works just fine with a new monitor.

I can't say I'm particularly satisfied that this was all caused by a bad (or rather an old) monitor, but at the very least this experience has gotten me back on Arch Linux!

Thanks for your help!

I ran into a similar issue with my RX 5700 XT and a bad/old DisplayPort cable, so if I were to impart any wisdom to someone who might stumble upon this thread:

Make sure that you're using a newish monitor and a newish DisplayPort cable!

orlfman · 2021-02-02 01:46:50

Nevermind

Last edited by orlfman (2021-02-02 09:47:22)

Lone_Wolf · 2021-02-02 13:21:22

Glad you figured it out, telebooth .

Please prepend [SOLVED] to the title (edit first post of the thread)

Arch Linux

#1 2021-01-26 22:20:08

RX 6900 XT Black Screen/ No Output without nomodeset

#2 2021-01-26 23:03:47

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#3 2021-01-26 23:16:26

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#4 2021-01-26 23:32:47

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#5 2021-01-26 23:40:33

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#6 2021-01-26 23:48:12

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#7 2021-01-27 00:07:11

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#8 2021-01-27 00:20:44

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#9 2021-01-27 23:11:13

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#10 2021-02-02 01:46:50

Re: RX 6900 XT Black Screen/ No Output without nomodeset

#11 2021-02-02 13:21:22

Re: RX 6900 XT Black Screen/ No Output without nomodeset

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