Fullscreen(scanout): display engine can still be overwelmed

[Vixea]

A follow up to what I understood should've or was likely to have been fixed(at least with more powerful dgpu display engines?) by #1020
Anyway the description of the problem from what I understand:
When in fullscreen or scanout the display engine in the GPU can be overwhelmed causing dropped, stutters, (whatever you wanna call it) frames. If it can't be reproduced on a desktop system I would recommend trying an all amd laptop(one igpu and dgpu) which is what I'm currently reproducing it with

[Drakulix]

Yeah, it would be great if I had all the hardware in the world to test on. /s

Jokes aside, so you are experience stuttering on an AMD system with an iGPU and dGPU for a fullscreen title?

Can you tell me some more:

• What framerate/resolution are you targetting?
• VRR?
• Are there additional displays?
• What gpu is the display connected to, which gpu is the game running on?
• Anything suspicious in cosmic-comp or kernel logs?
• Can you get a dump of drm_info, while your game is running (e.g. via ssh), so we can easily confirm that direct scanout is actually in use?

Thanks for the bug report. :)

[Vixea]

1920*1200 at 165 Hz
Auto
No
Maybe I'm seeing a whole lot of repeating(what looks like the) amdgpu driver initing - https://pastebin.com/cEzWkEm9

https://pastebin.com/ZvfZGd0R

[Vixea]

https://pastebin.com/fT1DHPhn
Mild concern noticed this after quickly entering fullscreen on a video and checking the logs

[Vixea]

@Drakulix friendly ping, sorry if you're busy

[Vixea]

Yep it's a scan out issue no problem with the disable scan out env var, nope just didn't reproduce it with the game however watching a video did it so nope nevermind

[Drakulix]

I am not sure what to tell you, the kernel logs look like this might be an amdgpu bug.

The drm_info log (and your tests with disabling scanout) should that direct scanout is in fact active. The log also confirms that VRR is active, but I am not sure, if that has any impact on the issue you are seeing.

I recommend to turn of scanout via the environment variable and possibly open a mesa/amdgpu issue.