Early kms might be incompatible with Phoenix
Description:
Since mkinitcpio v32 Arch Linux defaults to early kms, thus the amdgpu module gets loaded before the rootfs gets mounted.
Phoenix APUs require the vcn_4_0_2.bin.zst
firmware to be available otherwise amdgpu fails to load.
That didn't use to be the case back in November 2023, but apparently something changed.
Why does Arch Linux default to early kms? What's the advantage? Arch's kernel enables simpledrm so even if we switch to late kms by removing the hook we can still use the framebuffer built by the UEFI GOP driver early in the boot.
Additional info:
- package version(s): v32+
- config and/or log files: https://gitlab.freedesktop.org/drm/amd/uploads/2f5111a99740145fd3f3df6befe97467/journal.log
- link to upstream bug report, if any: https://gitlab.freedesktop.org/drm/amd/-/issues/3297
Steps to reproduce:
- Keep the default
kms
hook in/etc/mkinitcpio.conf
- Don't add
/lib/firmware/amdgpu/vcn_4_0_2.bin.zst
toFILES
- Reboot and watch gdm failing to load