Graphics
See also
Power saving for hybrid graphics is covered in Hybrid graphics.
Screen flicker
Nvidia dGPU
Affected hardware: a Dell Latitude 5480 user reported “screen flickers at an inconsistent rate, though not that sporadic”.
Solution: disable ASPM on battery in the configuration
PCIE_ASPM_ON_BAT=default
AMD GPU
Symptom: screen flickers briefly when the power source changes.
Solution: disable the radeon driver’s power saving:
RADEON_DPM_STATE_ON_AC=performance
RADEON_DPM_STATE_ON_BAT=performance
Refer to Graphics for details.
Note
Affects radeon driver only, not amdgpu.
Kernel message “ERROR radeon: ring 0 test failed’ on AC power”
AMD GPU
Affected hardware: a Lenovo Ideapad 300 (Intel / Radeon hybrid graphics) user reported this issue.
Solution: disable DPM like this
RADEON_POWER_PROFILE_ON_AC=""
Note
Affects radeon driver only, not amdgpu.