Failure to Switch to External Monitor (DP-4) on Niri 0.1.7

[coleleavitt]

Failure to Switch to External Monitor (DP-4) & Shader Compilation Errors on Niri 0.1.7 Startup

Description

When starting Niri version 0.1.7 (v0.1.7-59-g324029c) on a system with hybrid graphics (Intel + NVIDIA), shader compilation errors occur for custom close and open shaders. This prevents proper rendering and impacts functionality (not being able to display on DP-4).

Environment

• Niri version: 0.1.7 (v0.1.7-59-g324029c)
• OS: Arch Linux (Kernel 6.10.2-arch1-1)
• CPU: 12th Gen Intel Core i9-12900HX
• GPU:
  • Intel Alder Lake-HX GT1 [UHD Graphics 770] (driver: i915)
  • NVIDIA GA104GLM [RTX A4500 Laptop GPU] (driver: nvidia v: 555.58.02)
• Display:
  • eDP-1 (3840x2400)
  • DP-4 (1920x1080)

Steps to Reproduce

1. Start Niri
2. Attempt to set display output for DP-4 using niri msg outputs

Observed Behavior

Shader compilation errors occur for custom close and open shaders:

[GL] 0:32(25): error: niri_tex_curr' undeclared [GL] 0:32(15): error: no matching function for call to texture2D(error, vec2)'; candidates are: [GL] 0:32(15): error: vec4 texture2D(sampler2D, vec2) [GL] 0:32(15): error: vec4 texture2D(sampler2D, vec2, float)

Similar errors occur for niri_tex_next.

Expected Behavior

Shaders should compile successfully without errors, allowing proper rendering and display configuration.

Relevant Log Output

Niri Log: https://paste.rs/1vDoC.txt

Additional Context

• The issue occurs immediately on startup
• Both custom close and open shaders are affected
• The error suggests undefined variables (niri_tex_curr and niri_tex_next) in the shader code
• System uses hybrid graphics (Intel + NVIDIA)

Possible Causes

1. Incompatibility with hybrid graphics setup
2. Recent changes in shader compilation process or dependencies
3. Incorrect GPU selection or initialization on startup

Proposed Solutions

1. Review and update shader code to ensure all variables are properly declared
2. Implement a fallback mechanism for systems with hybrid graphics
3. Add debug logging for GPU selection and initialization process
4. Consider adding a configuration option to force using a specific GPU

Questions for Investigation

1. Are there any known issues with shader compilation on hybrid graphics systems?
2. Has the shader code been modified recently to account for different GPU setups?
3. Is there a way to force Niri to use a specific GPU (e.g., the NVIDIA GPU) for rendering?
4. Are there any specific NVIDIA driver settings that need to be adjusted for proper Wayland/Niri compatibility?

Related Threads

https://github.com/YaLTeR/niri/issues/567

[YaLTeR]

for custom close and open shaders

Could you upload the config?

[coleleavitt]

for custom close and open shaders

Could you upload the config?

https://paste.rs/tgvVk.txt

[YaLTeR]

You have errors in your custom shaders:

• in window-open you use niri_tex_next but there's no such variable in the open shader, the correct one is niri_tex
• in window-close you use niri_tex_curr but there's no such variable in the close shader, the correct one is niri_tex

[coleleavitt]

Issue was fixed, primary issue with screen tearing and artifacting:

debug {
  wait-for-frame-completion-before-queueing
}

thanks to @YaLTeR