Reset of manually set refresh rates / Better handling of manually set refresh rates

[romangg]

In GitLab by @ms178 on Aug 25, 2022, 15:13

With current Kdisplay-git master manually set refresh rates which are lower than the maximum allowed by the display get reset to the highest refresh rate from time to time. I usually set a rate of 119,997 Hz which then gets changed back to 165 Hz. It can take several reboots to see this, but as I usually compile daily several new Kernel or Mesa versions and reboot, so I see this quite often.

A related issue is that I then have to first set the refresh rate to automatic and only then re-set it to the desired 119,997 Hz otherwise it would not apply. This can be tested out with the Aquarium WebGL benchmark in the browser. It would be more intuitive if I hadn't to go through the round trip through the automatic setting and could set it directly to 119,997 Hz (and to keep it once it is set).

[romangg]

In GitLab by @ms178 on Oct 6, 2022, 14:04

I found a way to reproduce this problem reliably:

• this is with an HP x27 q, WQHD and connected via DP to my Vega 56, the refresh rate is manually set to 119,997 Hz
• open the unigine-heaven benchmark with FullHD resolution, set it to fullscreen mode
• run the benchmark once; when you get back to the desktop, the refresh rate is now automatically re-set to the maximum of the display, which is 165 Hz which provides a worse / stuttery experience on that display in games than 119,997 Hz

[romangg]

That might be due to the benchmark changing the refresh rate on its own.

[romangg]

Or at least this triggers the faulty behavior and we don't handle it correctly.

[romangg]

In GitLab by @ms178 on Oct 21, 2022, 13:20

FWIW, I could also reproduce this issue with stock Kwin/kscreen.