[PATCH 4.8 24/35] drm/amdgpu: fix check for port PM availability

4.8-stable review patch. If anyone has any objections, please let me know. -- From: Peter Wu commit 7ac33e47d5769632010e537964c7e45498f8dc26 upstream. The ATPX method does not always exist on the dGPU, it may be located at the iGPU. The parent device of

[PATCH 4.8 24/35] drm/amdgpu: fix check for port PM availability

4.8-stable review patch. If anyone has any objections, please let me know. -- From: Peter Wu commit 7ac33e47d5769632010e537964c7e45498f8dc26 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