[Intel-gfx] [PATCH 10/10] drm/i915: Kill off actually requiring AGP

[Ben Widawsky]

On Fri, 26 Oct 2012 00:47:31 +0200
Daniel Vetter <daniel at ffwll.ch> wrote:

> On Thu, Oct 25, 2012 at 03:39:08PM -0700, Jesse Barnes wrote:
> > > > It would be cool to actually remove the dep for pre-gen6.  I
> > > > don't think we need this patch in either case.
> > > > 
> > > 
> > > Your linker is going to complain without it, unless I don't
> > > follow your meaning.
> > 
> > I mean unless we split the driver into gen6+ and pre-gen6 (with a
> > config option or otherwise), we can't really kill the dependency
> > unless we actually pull the rest of the AGP stuff we need into
> > i915.  I'd kind of like to do the latter, but the non-KMS configs
> > would break.
> 
> Also, some kms config actually break because we've managed to ship
> userspace that uses kms, but in parts also still uses the legacy
> drmMap api. Which in our case means we need to have a working (but
> fake) agp driver around. This entire thing is one giant mess, but I
> think with the gen6+ stuff moved it's about as good as it will get.
> And I don't mind the old crap too much, we have an entire dungeon
> full of them in i915_dma.c, too ;-)
> -Daniel

The idea (as discussed on IRC) was to provide something like a
CONFIG_GEN6 which will properly detect and error out for older
platforms. This would allow embedded systems to save on the AGP size
when they are trying to store everything in flash.

Anyway, for now, I think we all agree that this is unnecessary, but if
someone building an embedded system with i915 graphics wants to save
roughly 500k of binary data size (and some smaller amount of runtime
memory)...

-- 
Ben Widawsky, Intel Open Source Technology Center