Bluetooth HID Mouse Latency on Fedora 44 + GNOME 50 Wayland Resolved by Combined Wi-Fi Power Saving and AMDGPU Workarounds

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System configuration:

  • Fedora 44
  • GNOME 50
  • Wayland session
  • AMD GPU using the amdgpu driver
  • MediaTek MT7921 Wi-Fi/Bluetooth chipset
  • Microsoft Surface Arc Mouse connected over Bluetooth HID

Observed issue:
After upgrading to Fedora 44, severe Bluetooth mouse latency and intermittent cursor stuttering were observed under GNOME Wayland.

The issue initially appeared to be Bluetooth-related. However, investigation showed no obvious Bluetooth transport failure:

  • no Bluetooth disconnects,
  • no HCI resets,
  • no btusb crashes,
  • no firmware loading failures,
  • no HID reconnect loops.

Relevant observations:

  • mt7921e firmware loaded correctly
  • Bluetooth controller initialized successfully
  • Surface Arc Mouse detected properly as a Bluetooth HID device
  • No clear Bluetooth transport or RF errors were visible in journalctl or dmesg

Firmware information:

  • MediaTek MT7921
  • Wi-Fi firmware build time: 20260224103145
  • Bluetooth firmware build time: 20260224103448
  • Fedora package: mt7xxx-firmware-20260519-1.fc44

Workarounds tested:
Disabling Wi-Fi power saving improved the situation:

sudo iw dev wlp98s0 set power_save off

Adding the following AMDGPU kernel parameter also improved the situation:

amdgpu.dcdebugmask=0x10

Applied with:

sudo grubby --update-kernel=ALL --args=“amdgpu.dcdebugmask=0x10”

Result:
The issue was fully resolved only when both workarounds were applied together:

  1. Wi-Fi power saving disabled on the MT7921 interface
  2. AMDGPU DC debug mask enabled through the kernel command line

After applying both:

  • Bluetooth mouse latency disappeared
  • Cursor movement became smooth again
  • Desktop responsiveness improved significantly
  • No Bluetooth reconnection or transport errors were observed

Current hypothesis:
The issue may involve an interaction between:

  • MediaTek MT7921 Wi-Fi/Bluetooth coexistence,
  • Wi-Fi power management,
  • AMDGPU Display Core behavior,
  • GNOME Wayland compositing,
  • input scheduling or frame timing.

The Bluetooth subsystem itself appears stable, but latency becomes visible at the user-input level.

Additional notes:

  • The Bluetooth mouse remained connected during the issue
  • The problem manifested as latency and cursor stuttering, not as disconnection
  • A single workaround was not sufficient in this case
  • The combination of Wi-Fi power saving disabled and amdgpu.dcdebugmask=0x10 resolved the issue

This report is submitted in case it helps identify a regression or interaction affecting Fedora 44 systems using GNOME 50 Wayland, AMDGPU, and MediaTek MT7921 Wi-Fi/Bluetooth hardware.