[PATCH 2/3] acpi_video: Intel video is not always i915

[Alan Cox]

On Wed, 25 Apr 2012 13:40:18 +0100
Matthew Garrett <mjg59 at srcf.ucam.org> wrote:

> On Wed, Apr 25, 2012 at 01:24:38PM +0100, Alan Cox wrote:
> 
> > Because as I said before there are two drivers involved and you may only
> > have one compiled into your kernel. If you have
> > 
> > CONFIG_DRM_GMA500=y
> > CONFIG_DRM_I915=n
> > 
> > you want the acpi stuff to autoregister even if an i915 is found, but not
> > if a GMA500 is found. Ditto the reverse.
> 
> No you don't - there's various platforms that will hang if you do that. 
> It's necessary to make sure that the DIDL fields are set up before 
> calling any ACPI video functions on opregion hardware.

Then the existing driver code is already broken, because it ifdefs out
the check if i915 is not compiled for the kernel.

Alan