I recently got a new desktop computer that has an AMD GPU (6700xt) and it has the same issue with “no display”… sometimes.
If you try multiple boots, does it work some of the time? That’s the case for me. (I was able to boot the installer just fine, but after install, the “no signal” would hit me some of the time.)
My new desktop is running a fresh install of Fedora 36 Silverblue and it intermittently has “no signal” while booting right after grub. Before grub (EFI boot splash) and after booting when there is a signal, everything’s fine. Around 1/4 to 1/2 the boots are met with “no signal” and the GPU is apparently not powered. DisplayPort and HDMI both do not work when it’s in this state.
On a successful boot, it works perfectly, for many hours. Suspend and resume work fine too, so it really looks like some problem initializing the GPU during boot.
At first, I was worried that it might be a hardware issue with the computer, as it’s new… but it might also be a cable problem or just a finicky monitor + GPU combo in my setup. I do get some issues with my work and personal laptops hooked up to my external monitors too, but they still work (although sometimes with weird resolutions or they don’t see the monitor correctly). However, my laptops have fallback displays (internal screens) and my desktop doesn’t. And they’re Intel iGPUs, whereas my new desktop is using an AMD card.
But if you and others are having similar issues, then it might be something with the AMD driver in the kernel. Additionally, Fedora changed the DRM/KMS boot support:
But if it’s happening in Arch for you too, then it’s probably not the Fedora 36 changes.
I haven’t found a solution yet. Perhaps there’s some initialization in Fedora’s boot that’s causing a problem.
On a hunch, I removed the
rhgb option from grub, thinking that it might not like the modeswitching from bios to the password prompt (as my disk is encrypted). But this is a wild guess. I’ll test it later, when I’m back on it and will try to remember to check back here soon with how things are going here as well.
In summary, it could be a number of things:
- Bad hardware (probably not, if we’re both having this problem, and if it only happens after grub, and in my case, only sometimes)
- Bad cable (it’s a possibility… perhaps something in recent software changes is more sensitive to our cables)
- Picky monitors and/or GPUs and/or cables in combination
- Fedora 36’s DRM/KMS changes
- Kernel changes with the AMD driver
I think you and I have most likely knocked down the possibilities to kernel changes between 5.15.13 to 5.16.2 (and Fedora is on 5.17.6-300 here). Since it’s likely not something that would go into a x.x.y point release, it’s probably something that changed as of 5.16.
So: What changed? Well, here’s an article with info:
It does change AMD drivers a good bit and even has DisplayPort 2.0 changes (which means they might’ve touched code for initializing DisplayPort output, which could have possibly also affected HDMI output too).
It’s definitely possible that there is a kernel regression in video support that might hit some of us more than others.