gpu_busy_percent always reports 100 on Vega 3
Brief summary of the problem:
On my iGPU (Vega 3) cat /sys/class/drm/card0/device/gpu_busy_percent
always reports 100
, no matter the actual load. This impacts almost any load monitoring application like MangoHud, except for radeontop, which uses libdrm_amdgpu for retrieving the load. This issue persists not only on the system reported here, but also on every single other distro I've ever tried (Ubuntu/Fedora/Arch/Manjaro/etc.)
Hardware description:
- CPU: AMD Ryzen 3 3200U Mobile Processor
- GPU:
02:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Picasso/Raven 2 [Radeon Vega Series / Radeon Vega Mobile Series] [1002:15d8] (rev c4)
- System Memory: DDR4-2666 4+16 (20 in total, 2 reserved for VRAM)
- Display(s): Builtin laptop display
- Type of Display Connection: Builtin laptop display, not sure
System information:
- Distro name and Version: latest Debian Testing (issue persists on stable)
- Kernel version:
Linux <hostname> 6.1.0-5-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.12-1 (2023-02-15) x86_64 GNU/Linux
- Custom kernel: N/A
- AMD official driver version: N/A
How to reproduce the issue:
- Get a laptop with an R3 3200U
- Run
cat /sys/class/drm/card0/device/gpu_busy_percent
- It will always print
100
, no matter the actual load