Display unresponsive for 5 minutes after boot

[headfirst7231]

I’m seeing an issue where my display is completely unresponsive for around 5 minutes after boot. The system itself seems to be responsive, since the keyboard status lights such as CapsLock, FnLock, and mute work fine.

The details of my system:

My system is fully updated:

❯ sudo pacman -Syu
[sudo] password for jlee: 
:: Synchronizing package databases...
 endeavouros is up to date
 core is up to date
 extra is up to date
 multilib is up to date
:: Starting full system upgrade...
 there is nothing to do

My graphics setup:

❯ inxi -G
Graphics:
  Device-1: Advanced Micro Devices [AMD/ATI] HawkPoint1 driver: amdgpu
    v: kernel
  Device-2: Luxvisions Innotech Integrated Camera driver: uvcvideo type: USB
  Display: wayland server: X.org v: 1.21.1.21 with: Xwayland v: 24.1.9
    compositor: kwin_wayland driver: X: loaded: amdgpu unloaded: modesetting
    dri: radeonsi gpu: amdgpu resolution: 2880x1800~120Hz
  API: EGL v: 1.5 drivers: kms_swrast,radeonsi,swrast
    platforms: gbm,wayland,x11,surfaceless,device
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 25.3.4-arch1.1
    renderer: AMD Radeon 780M Graphics (radeonsi phoenix LLVM 21.1.6 DRM 3.64
    6.18.7-arch1-1)
  API: Vulkan Message: No Vulkan data available.
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor wl: wayland-info
    x11: xdpyinfo, xprop, xrandr

Some other points:

• The issue persists regardless of X11 or Wayland, so it is not a window manager issue.
• I don’t see the issue after waking up the system after sleep, but it happens consistently after a fresh reboot or a fresh user session after logging out and back in.
• Sometimes the display stays unresponsive after 5 minutes, but I can ‘force’ it to wake up by connecting an external display during the unresponsive state.
• The latest mesa drivers are installed

What could be causing this issue, and what are some logs I can check to start debugging?

[headfirst7231]

After some experimentation guided by some back-and-forth with ChatGPT, I found that editing GRUB’s config file resolved the issue. Specifically:

❯ sudo nano /etc/default/grub

Then, I appended the amdgpu.dcdebugmask=0x10 parameter to GRUB_CMDLINE_LINUX_DEFAULT:

GRUB_CMDLINE_LINUX_DEFAULT='nowatchdog nvme_load=YES resume=UUID=a740cfaa-366d-4a5e-b92c-7ff22ebb68f7 loglevel=3 amdgpu.dcdebugmask=0x10'

Then I regenerated the config file and restarted the device:

❯ sudo grub-mkconfig -o /boot/grub/grub.cfg

❯ sudo reboot

Doing this resulted in the display freeze issue going away.

I’m still curious why this happened in the first place though. It seemingly started randomly today out of nowhere while I was managing my ebook library on Calibre.