https://bugs.freedesktop.org/show_bug.cgi?id=98505
--- Comment #11 from Peter Wu peter@lekensteyn.nl --- (In reply to Alex Deucher from comment #10)
(In reply to Peter Wu from comment #7)
Created attachment 127678 [details] [review] [review] amdgpu patch that checks whether the new interface can be used for PM
PCIe port PM is not enabled because this BIOS is pre-2015: 12/04/2014 The BIOS seems to be able to report support for lots of things (can you post a fuller dmesg that include the supported functions?):
Can we bump the bios white list to 2014? Windows enabled Hybrid graphics on windows 8.x as well as 10, and a number of preliminary win10 systems have 2014 bios versions. I'd prefer that to doing all of these hacks in the drivers.
Lowering the minumum from 2015 to 2014 should work for nouveau: https://lists.freedesktop.org/archives/nouveau/2016-July/025619.html
You can try to ask Mika, see v4.7-rc2-3-g9d26d3a. Maybe the presence of a power resource (_PR3 or flags.power_resources) can be used as a hint whether to enable port PM.