Re: [PATCH v3 0/2] efi/x86: Call set_os() protocol on dual GPU Macs

Aditya Garg
2024-07-17T16:52:56Z

Hi Ard

> Hi,
>
> Is this a theoretical concern? Or are you aware of any user that is
> actually affected by this?

We had a Mac Mini user who wasn't able to use hybrid graphics
on his Mac after using the eGPU. So no, it's not a theoretical concern
> In any case, given the niche nature, enabling this more widely by
> default does not seem like a great approach, as the risk for
> regressions outweighs the benefit.
>
> I could imagine the use of a EFI variable to opt into this, would that
> work? It would have to be set only once from user space (using
> efivarfs)

I'm not really sure about efivars here, but am ready to test. As long as
it doesn't break booting of macOS or Windows, I don't find it an issue.
macOS may also reset the variable, again have to verify by testing the same.
I guess it will also get reset if a users resets their NVRAM.