I happen to have the exact same monitor as you, based on your bug report.
I was able to enable HDR in Helldivers 2 by
Enabling HDR in KDE display settings (requires Wayland)
Using this Steam command line: gamescope -w 3440 -h 1440 -f -r 165 --hdr-enabled -- %command%
Enabling the setting in game, in display settings
The other arguments in your command line seem unnecessary and I would recommend removing them as they could be possible error sources. Also note that environment variables such as DXVK_HDR=1 should be put in front of everything, not passed to gamescope as a parameter.
However, I was not able to reproduce the issue you describe. The visual difference was clearly noticeable the moment HDR was enabled, but gamma is stable for me. I am on Nvidia, however, and used to things just working. I tested some HDR on an AMD card a year ago on Windows and it wasn’t working well either.
For testing, you could disable some graphics card features, such as FFSR, Fluid Motion Frames, Anti-Lag, Boost, Chill… Everything basically. You don’t really need them, because Radeon cards rely more on raw power than optimization. And many of these features cause more trouble than they are worth, especially FFSR.
I basically enable HDR the same as you. I tried to use the above command HDR works but the issue is still present.
Did you try to CAP your Framerate to 90FPS in game for example? As long the FPS is above 100 you will not see the gamma flicker. But if you set it at 90, even if stable the flicker is present.
Aren’t those features at driver level? On Linux I think you cant even use them.
I did some more testing to see if I could somehow provoke gamma fluctuations as you describe them, but it wasn’t possible. It just works. Here’s what I tried:
FPS uncapped, capped at 90, capped at 60 (in-game)
VSync on/off
Quality presets from low to ultra
Upscaling from low to native resolution to super-sampling (DLSS)
Enabling/Disabling features such like motion blur, bloom, depth of field, etc.
Good question about how to manage the graphics card features. In Windows you can use Adrenaline to control your AMD card, I would assume there is something on Linux for this?
However, according to ArchWiki - Gamescope it seems that neither FSRR upscaling nor frame generation is used by default, unless you enable it. My prime suspect just got an alibi.
Any AMD Readeon users here who could check if they can reproduce this on their system?
Edit: One more thing you could try is different proton versions.
You can choose those from the game properties in Steam under “Compatibility”.
For “Proton Experimental”, you could also try the “bleeding edge” version. You choose this one, by finding “Proton Experimental” in you Steam Library (Tools, not Games) and going to Properties → Beta Versions.
There are also alternative Proton versions such as proton-ge or proton-tkg. They can be installed through Garuda Rani → Gaming → WINE.
I’ve never needed anything else than the regular Proton Experimental, but proton-ge seems to be very popular. There ought to be a reason for that…
Mate, many thanks for trying to replicate/test and help out on this! Much appreciated, I own you a beer just for trying.
I was actually able to fix this believe it or nor…
One of the KDE devs replied to the BUG and pointed it could be a gamescope issue to try to disable HDR in gamescope and run the game.
He has right, even if HDR is disabled the flickering is still present. This pointed me to proper direction and I found an issue opened on the official gamescope repo.
Which after reading looks like gamescope can introduce VRR flicker due to nesting. I turned on my monitor’s built-in refresh rate OSD, and per it the Frame rates were all over the place even tho in game they were stable 90.
However matte-schwartz pointed out one interesting parameter --adaptive-sync
I checked the gamescope help
–adaptive-sync Enable adaptive sync if available (variable rate refresh)
I set the parameter: gamescope -w 3440 -h 1440 -f -r 165 --adaptive-sync --hdr-enabled -- %command%
= No flicker
I tried as well same parameter with using gooverlay: gamescope -w 3440 -h 1440 -f -r 165 --adaptive-sync --hdr-enabled -- %command%
= No flicker
I tried as well to set mangoapp as a parameter gamescope -w 3440 -h 1440 -f -r 165 --adaptive-sync --hdr-enabled --mangoapp -- %command%
= No flicker
And the flickering is gone. So looks like in my case this was a user mistake. If gamescope is used with a VRR monitor e.g Adaptive sync is turned on, gamescope has to have this parameter explicitly set otherwise VRR is broken and causes insane flicker bellow 100FPS.
Its still weird that you have the same monitor but not seeing this behavior. But who knows it could be some different triggers ~ dependencies causing this.
Anyway I hope if somebody has similar pain, with gamescope and VRR, this topic will help.
Once again many thanks specially to you for T-shooting with me.
