GTA IV: Colour flickering on Proton Experimental

[lukelmy]

Compatibility Report

• Name of the game with compatibility issues: Grand Theft Auto IV: The Complete Edition
• Steam AppID of the game: 12210

System Information

• GPU: AMD 6900 XT
• Driver/LLVM version: AMDGPU stack 22.20
• Kernel version: 5.15.0
• Proton version: Proton Experimental

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

Symptoms

When starting game with Proton Experimental, colour flickering can be observed. However, images are normal when using Proton 7.0-4. The problematic shader module is found with Renderdoc. If NAN judgement is added before extended instruction NMin(or NClamp) instead of only NMin(or NClamp) in the spirv-dis of problematic shader module, the image is normal. Guessing it's a SPIR-V generated issue.

The original spirv-dis and the modified spirv-dis of the problematic shader module on Proton Experimental are listed as follows: spv_pass.txt spv_fail.txt

Reproduction

• Start a new game

[mbriar]

This is expected if you use the proprietary vulkan driver, which does not support VK_EXT_attachment_feedback_loop_layout (yet?). It shouldn't happen with RADV, which is also the recommended driver for proton in general.

[kisak-valve]

Hello @lukelmy, we're using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to https://github.com/ValveSoftware/Proton/issues/350#issuecomment-1289037251.