You are not logged in.

#1 2019-12-02 20:13:05

tylerroche
Member
Registered: 2019-07-09
Posts: 13

[Solved] i3 Screen flashing and tearing with compton / picom 19

GPU, drivers, and screen setup: NVidia GTX 1060, nvidia drivers 440.36-2, two monitors side by side with xrandr, one ar 75hz, one ar 60hz (Problem still occurs when both set to 60hz)

Compton version: picom-git 1281_Next_2019.11.30-1 (from AUR)

Compton configuration:
Minimal : https://pastebin.com/k665mkmz
Normal : https://pastebin.com/u1KdTJ77
3rd: https://pastebin.com/Vi20Awm0

Steps of reproduction

I have updated my system today and after a restart, compton or picom as it has been renamed has not been working. The main issue happens when the back end is set to glx which makes my primary monitor go black and flicker (Normal Config). When I use the minimal config, glx works but with some screen tearing and setting the back end to xserver makes the tearing worse. Config 3works the best however, there are still tearing issues which is especially noticeable in Firefox

I would expect no tearing and each screen to be at a different refresh rate as it was before the update.
Current Behavior & Other details

I have tried to change to a minimal config which has helped a small amount but I suspect there could be an issue with mesa, nvidia drivers or compton. If it would be useful to try a previous version of anything please let me know

Last edited by tylerroche (2019-12-02 21:46:04)

Offline

#2 2019-12-02 20:40:38

seth
Member
Registered: 2012-09-03
Posts: 13,080

Re: [Solved] i3 Screen flashing and tearing with compton / picom 19

Your GPU has only one crtc, it cannot sync to two outputs (that's a HW limitation and didn't work before the update either) - exporting __GL_SYNC_DISPLAY_DEVICE will allow you to control the sync'd output.
That's not to say there's not possibly a bug in compton.

Judging from the configs, your main issue is probably the blur config (black background). For the "minimal" config, the refresh rate could have been misdetected (try to set it by hand) also 75fps on a 60Hz output or vv. will give you a nice tearline wandering across the screen (while w/ 60Hz you stand a chance that both outputs have similar vlank times, esp. when they're activated at the same time.
For the 3rd config you simply disabled vblank, what will get you random tearlines jumping across the outputs, wat makes it less noticable.

FF will render in GL itself, if it also syncs (to the wrong refreshrate) you'll have similar timing conflicts.

=> set both outputs to 60Hz, enforce that rate in compton (use the exact value from xrandr if compton allows for FP notation) and use __GL_SYNC_DISPLAY_DEVICE to inform the driver to your preferred output (though I think it's the primary tagged one by default)

Offline

#3 2019-12-02 21:39:00

tylerroche
Member
Registered: 2019-07-09
Posts: 13

Re: [Solved] i3 Screen flashing and tearing with compton / picom 19

Thanks for the answer, I have tried the minimal settings in picom rather than compton and forcing 60hz (through nvidia x server) makes the tearing go away. I have not set GL_SYNC_DISPLAY_DEVICE in cli but I think thats set in nvidia config. I will try to get it working with two different refresh rates though

Offline

#4 2019-12-02 21:42:33

tylerroche
Member
Registered: 2019-07-09
Posts: 13

Re: [Solved] i3 Screen flashing and tearing with compton / picom 19

The displays will work at any refresh rate now, the only downside is I have to force composition pipeline. I am just unsure if it is better to force full composition pipeline

Offline

#5 2019-12-02 21:44:13

seth
Member
Registered: 2012-09-03
Posts: 13,080

Re: [Solved] i3 Screen flashing and tearing with compton / picom 19

Ah, it's yetanotherfork - I thought this was just a pointless rename that I would ignore ;-)
In that case there's oc. a massive potential for "new" bugs since it's essentially a different codebase.

Edit: the full composition pipeline will require more energy and yield more heat.

Last edited by seth (2019-12-02 21:47:06)

Offline

#6 2019-12-02 21:45:50

tylerroche
Member
Registered: 2019-07-09
Posts: 13

Re: [Solved] i3 Screen flashing and tearing with compton / picom 19

Yeah, compton has been changed to picom and was simlinked to the picom binary in the latest update

Offline

Board footer

Powered by FluxBB