drm/radeon: fix check for port PM availability
commit
bcfdd5d5105087e6f33dfeb08a1ca6b2c0287b61 upstream.
The ATPX method does not always exist on the dGPU, it may be located at
the iGPU. The parent device of the iGPU is the root port for which
bridge_d3 is false. This accidentally enables the legacy PM method which
conflicts with port PM and prevented the dGPU from powering on.
Ported from amdgpu commit:
drm/amdgpu: fix check for port PM availability
from Peter Wu.
Fixes: d3ac31f3b4bf9fad (drm/radeon: fix power state when port pm is unavailable (v2))
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>