Running as daemon won't allow other full screen applications to update the screen by flipping

[allan-null]

tl;dr: Running xfdashboard as daemon won't allow other full screen applications to update the screen by flipping, consequently making impossible for the video driver to enable G-SYNC.

Hello. It is nice to have a good looking dashboard in a lightweight system like XFCE, but lately I am having a problem that might affect other users too. Basically, running xfdashboard as daemon will cause the same issue as running xfwm4 with compositing on: it won't allow other applications in full screen to update the screen by flipping, therefore making impossible for the video driver to enable G-SYNC. While I do have a bash script detecting applications and games running in full screen and then quitting xfdashboard, doing that loses most perks of running it as daemon in the first place. I am not a C programmer, but I can compile and test the as soon as a proposed fix appears. I mean, if you guys even consider this a bug.

[gmc-holle]

Hi,

thanks for your report. Sadly I do not understand the problem. What is G-Sync and how does it work? And why does compositing disturb these applications? Sorry, I don't know anything about these things and problems so I don't know how to fix it.

If I have done a mistake, xfdashboard should release any window redirections as soon as it goes into background. I think that is "compositing" and so it should be turned off if in background. I don't know if Clutter will do it also, although I also turned it off there when going to background.

But the best would be to explain G-Sync and the flipping problem and how (if possible with Intel GPU only) to reproduce the problem.

[allan-null]

I don't think Intel has a graphics technology similar to G-Sync (NVIDIA) and FreeSync (AMD). Those two are technologies for eliminating screen tearing without causing as much input lag as v-sync does. They are used mostly to improve gaming experience, and require compatible monitors in order to work.

I don't know much about FreeSync, but G-Sync is a tricky one to get working. In order to use this technology, the application you intent using with it must be covering the X screen completely. If even a pixel is being drawn by another application, it won't work. That is why it won't work when using a compositor, because it usually gets in between of the application running if full-screen and the X screen.

When I said "flipping", I was referring to one of the two ways I know my graphical drivers updates the screen: blitting and flipping. I am attaching two screenshots from mpv, in which the first one xfdashboard is running as daemon and the on the second one it is not.

Ps.: Obviously, a media player such as mpv doesn't take advantage of G-Sync. I am just using it as an example because it's easier to launch.

[allan-null]

I think this was a video driver issue, because after updating it the problem is gone. Thanks.