ValveSoftware
(SteamOS 3.6/3.7) Gamescope-session colorspace becomes washed out when toggling VRR on a modeset only exposed via USB-C DisplayPort 1.4 Altmode directly connected to monitor
Your system information
- Steam client version: 1725654351
- SteamOS version: SteamOS 3.6.12 and SteamOS 3.7
- Opted into Steam client beta?: Yes
- Opted into SteamOS beta?: Yes
- Have you checked for updates in Settings > System?: Yes
Please describe your issue in as much detail as possible:
Note: this appears to be a regression between linux-neptune-61 and linux-neptune-65, with linux-neptune-68 also affected.
When connecting my Steam Deck OLED directly to my Alienware AW3423DW ultrawide monitor via a Cable Matters Bidirectional USB C to DisplayPort 1.4 Cable 3.3 ft, Support 8K@60Hz, 4K@240Hz (Thunderbolt 4 to DisplayPort Cable, DisplayPort to USB C Cable) Black, I have several higher modesets available to me on my monitor that I cannot see in gamescope-session when using the official Steam Deck dock. When using one of these modesets, 3440x1440@175hz, gamescope-session will become washed out if I enable VRR and then disable VRR again from the right side menu of the Steam UI. This seems to be the only modeset which causes this specific issue.
Normal:
Washed out after VRR re-toggle - becomes washed out when disabled, stays washed out when re-enabled:
Disconnecting and reconnecting the monitor temporarily fixes the issue, although it'll return if you toggle VRR again.
This issue is not present on linux-neptune-61 when installed onto SteamOS 3.6 or SteamOS 3.7. I tried all the way down to linux-neptune-65-6.5.0-valve3 with no change in the problematic behavior.
For what its worth, when testing my ROG Ally under the same conditions (linux-neptune-65/68, SteamOS 3.6/3.7), I am unable to repro this bug which further leads me to believe it's limited to Vangogh and something in the kernel. I suspect this could probably be brought over to drm/amd, but I'm filing an issue here for now pending further debugging.
Please let me know if you'd like me to attempt some sort of bisect, although given the amount of patches that are pulled into linux-neptune branches, I doubt it would be much good.
Steps for reproducing this issue:
- Connect Steam Deck OLED directly to the monitor via a DisplayPort 1.4 USB-C cable
- Select a modeset that only becomes available to you when connected like this - for me, that's 3440x1440p@175hz
- With VRR enabled or disabled, toggle it into the opposite position via the Steam UI and you should observe the entire colorspace become extremely washed out
Relevant logging:
System report (taken after booting, docking, then changing VRR status): systemreport-20240907005953.txt
