Re: MacBook Pro 10,1 + i915

[Marek Vasut <marex@denx.de>]

Hi Chris,

> On Mon, Jul 01, 2013 at 10:39:14PM +0200, Marek Vasut wrote:
> > Hi guys,
> > 
> > I recently got the rMBP 10,1 model, it has two graphic cards:
> > 
> > 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core
> > processor Graphics Controller (rev 09)
> > 01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GT
> > 650M Mac Edition] (rev a1)
> > 
> > I'm running linux 3.10-rc7 . The nvidia works with nouveau, but I'd
> > prefer to switch the nvidia off altogether and use the intel GPU.
> > 
> > So far I arrived at the point where I disabled X11, mounted debugfs and
> > tried the vgaswitcheroo. With the nvidia still in operation, I see the
> > console. Unfortunatelly, I end up with a black screen after I run the
> > following command to switch to the intel GPU:
> > 
> > echo IGD > /sys/kernel/debug/vgaswitcheroo/switch
> > 
> > If I try to switch back to the nvidia card (using echo DIS > ...), the
> > screen remains black. This state persists until reboot. I suspect [1] is
> > the same bug, none of the hints there helped.
> 
> It is not that bug. This bug I believe is that no one has figured out
> how to reprobe the eDP and initialise it after a vgaswitch.

Do we have any kind of hints into what direction I should dig ? I mean, I went 
through the i915 source, went through David Airlies' patches [1] , but no 
success so far.

(User-unfriendly howto below, I hope this might help someone)

The interesting part is that if I do the following, the intel card operates 
correctly:
1) power down the mac
2) boot into OSX
3) install gfxcardstatus 2.2.1
4) select Discrete first ; then select Integrated card (a popup must be 
displayed in both cases in the top right corner indicating the operation 
succeeded)
5) reboot, start Linux

Now in Linux, I do have nouveau blacklisted and the nvidia blob is NOT installed 
at all. I
- modprobe nouveau
- mount -t debugfs debug /sys/kernel/debug
- echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

And I have 16W power consumption, therefore the intel card is in operation and 
nvidia is probably off. The laptop is still a little hot in linux, but that's 
OK.

Yet I'd prefer to avoid the above booting into macos and do all this in Linux. 
If you could give me any pointers, that'd be really appreciated.

Thanks!

[1] http://cgit.freedesktop.org/~airlied/linux/log/?h=switchy-wip

Best regards,
Marek Vasut