[Intel-gfx] [PATCH 2/3] drm/i915: disable drm agp support for !gen3 with kms enabled

[Daniel Vetter]

On Sun, Jun 24, 2012 at 07:57:26PM -0300, Eugeni Dodonov wrote:
> On 06/24/2012 03:51 PM, Daniel Vetter wrote:
> > +	/* Only enable AGP support for gen 3. */
> > +	if (intel_info->gen != 3) {
> > +		driver.driver_features &=
> > +			~(DRIVER_USE_AGP | DRIVER_REQUIRE_AGP);
> > +	} else if (!intel_agp_enabled) {
> > +		DRM_ERROR("drm/i915 can't work without intel_agp module!\n");
> > +		return -ENODEV;
> > +	}
> > +
> 
> <bikeshed>
> For the future generations of developers to touch gen3 (or something
> older than gen3 :)), I'd suggest to expand the comment to explain why we
> need it on gen3 and not on all the other gens. I haven't seen this
> commented in any other agpgart killing patches, so perhaps this would be
> the best place.
> </bikeshed>

Well, the older series that rips out the midlayer-ish drm agp
initialization had more justification - we need it to support dead-broken
XvMC on gen3, which is using the old drm add_map stuff to access bos, even
when kms is enabled (gasp!). I'll add this little blurb to the comment
when applying.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48