[bisected,regression] eDP garbage storm
Brief summary of the problem:
Quickly changing garbage displays on the integrated (eDP-attached) panel of the system. The garbage appears once the panel was been re-initialized, i.e. it works properly during the kernel boot phase and for the greeter (gtkgreet). However once entering a Sway session (keep in mind that gtkgreet is also using Sway), the garbage appears and stays. This is a regression detected when testing 5.13-rc5 in conjunction with another problem (see issue #1599 (closed)).
It's possible to trigger this even without any user interaction. The laptop firmware uses the display attached via USB-C by default, so if there is a display attached there the boot process (Dell logo, kernel log) is shown there. As soon as the amdgpu driver kicks in, it makes the integrated panel the primary display and disables the USB-C. With 5.13-rc5 the garbage storm starts as soon as this happens.
I recorded a short clip showing how the garbage storm behaves. If you frame-step through the MKV you see that there are short instances of the screen just displaying black: eDP_regression
Hardware description:
- CPU: Ryzen 7 4800H
- GPU: Renoir iGPU, Navi10 dGPU
- System memory: 32GB
- System firmware: 1.4.4
- Display(s): Integrated panel
- Type of Diplay Connection: eDP
System information:
- Distro name and Version: Gentoo x86-64
- Kernel version: 5.13-rc5
- Custom kernel: amdgpu patches applied (see issue #1599 (closed) for details)
- AMD package version: No package
- Firmware version: both Renoir and Navi10 are at 20.10 (currently the latest available in linux-firmware)
How to reproduce the issue:
See the summary, the crucial point here is that the panel needs to go through some sort of "re-initialization".