[Intel-gfx] [PATCH] ACPI/Intel: Rework Opregion support

[Dave Airlie]

>
> Read the changelog and thread on the patch that disabled this logic, the
> failure (or at least inconsistent behaviour with the expectations of the
> HP BIOS authors) appears to be in how we initialise ACPI on the HP
> machines that causes the initial value of lid state to be incorrect. Since
> one of the laptops that Dave tests drm-next on is a HP, he was bitten by
> the bug and temporarily (we hope) disabled the logic. Or else once again,
> we will continue to light up the panel on a closed laptop.

Yeah I've no idea if the ACPI implementation is wrong or not :-(

I suspects its the BIOS actually, the BIOS wants _INI called before _REG.
The ACPI video device isn't in the EC address space, so it ends up in the
default region address space. So we'd really need to know how Windows
sets up the _REG calls for the non-EC spaces and where its calls the _INI
methods wrt to that.

The thing is I think the actual ACPI lid device is fine, its just opregion isn't
updated until we get an event later.

Dave.