Re: [PATCH v2 4/5] apple-gmux: support MMIO gmux on T2 Macs

Lukas Wunner
2023-02-20T09:24:13Z

On Mon, Feb 20, 2023 at 09:44:54AM +0100, Hans de Goede wrote:
> On 2/19/23 14:39, Lukas Wunner wrote:
> > I believe the Mac Pro (the trashcan one) also contains a gmux and
> > an APP000B device in DSDT. I recall seeing a bug report due to a
> > splat in the gmux driver on that machine. Back then I confirmed
> > in the schematics that it does contain a gmux, though I think it's
> > only used for brightness, not GPU switching.
>
> Erm, the Mac Pro (the trashcan one) does not have an internal LCD
> panel, right? So I don't think the gmux will be used for brightness
> control there ...

Right. I see now that I even added a comment to apple-gmux.c on that
Mac Pro, I couldn't figure out back then what the gmux was for:

* (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
* dual GPUs but no built-in display.)

Thanks,

Lukas