[PATCH 00/11] Enable gpu switching on the MacBook Pro

[Matthew Garrett]

On Tue, Apr 21, 2015 at 11:58:20AM +0200, Lukas Wunner wrote:

> On MBPs, the panel is not connected to one of the gpus, but to the
> gmux chip (the "handler" in vga_switcheroo speak). Initially the gmux
> is switched to the discrete gpu. The integrated i915 gpu is therefore
> unable to detect the LVDS (or eDP) connector on bootup and switching
> to the integrated gpu will lead to a black screen. The solution is
> to temporarily switch the DDC lines to the integrated gpu when reading
> the EDID, which the gmux is capable of. Lack of support for this in
> vga_switcheroo is pretty much the only obstacle to get gpu switching
> to work on MBPs.

My testing suggested that changing the DDC lines didn't change auxch, so 
this approach doesn't work for eDP. Have you found otherwise?

-- 
Matthew Garrett | mjg59 at srcf.ucam.org