[Intel-gfx] [PATCH] drm/agp: agp-intel/i915: trim stolen space to 16M

[Jesse Barnes]

On Tue, 23 Mar 2010 10:53:20 +0800
Zhenyu Wang <zhenyuw at linux.intel.com> wrote:

> On 2010.03.22 11:17:46 -0700, Jesse Barnes wrote:
> > On my SDV, the BIOS allocates 128M of stolen space no matter what
> > settings I use.  This leaves very little aperture space available (at
> > least relatively so given my 30" + 24" desktop setup) for mapping
> > buffers in execbuf.
> > 
> > I've been using this patch for awhile to work around the problem, and
> > think it's a reasonable thing to apply.  We generally only need a small
> > amount of stolen space for the few things that need contiguous space,
> > the compressed frame buffer being the biggest.
> 
> Jesse, from Yakui's recent finding, the compressed fb size for Cantiga
> and Ironlake could be as large as 4096x2048 32bpc for 32MB, so some large
> fb size e.g 1900x1200 could be compressed. So max 16M for stolen may be
> too small?
> 
> I'll send out Yakui's patch later.

Yeah, if we need to bump the limit, that's fine.  We'd need to adjust
both the limit I added in AGP and the allocation size we try for in
i915_dma.c when we set up the compressed buffer.

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center