[Intel-gfx] [PATCH 2/4] drm/i915: Stop depending upon CONFIG_AGP_INTEL

[Chris Wilson]

On Wed, Jan 27, 2016 at 02:37:59PM +0100, Daniel Vetter wrote:
> The AGP_INTEL driver provides an interface for very old userspace to
> control the GART (though the GART itself was only ever emulated on Intel
> systems). The pci bridge discovery code is also used by the i915.ko
> driver to set up the GTT on old systems, but it does not require the
> old userspace interface. When i915.ko selects the old interface, it
> binds another user to the core GTT routines, and in particular creates a
> second reference to the scratch pages allocated. This hinders resource
> leak debugging for when we unload i915.ko as we want to assert that all
> DMA pages have been released, but we appear to leak because of the
> secondary interface which persists after i915.ko unloads.
> 
> All i915.ko users do not require the old /dev/agpgart interface so stop
> selecting it and simplify our debugging by dropping the historical
> baggage.
> 
> Note that by selecting AGP=n it was already possible to unselect
> AGP_INTEL. But since we've dropped support for any of the AGP stuff
> long ago there's really no point for this any more.
> 
> Also note that we still need INTEL_GTT, which is the underlying,
> share, driver for the graphics GART on gen1-5.
/share,/shared
 
> v2: Entirely new commit message (Chris, Ville).
> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre