[Intel-gfx] [PATCH] drm/i915/bdw: Don't allow the FBC base to be 0

[Ben Widawsky]

On Fri, May 02, 2014 at 04:00:25PM +0300, Ville Syrjälä wrote:
> On Fri, May 02, 2014 at 09:38:11AM +0100, Chris Wilson wrote:
> > On Fri, May 02, 2014 at 11:19:27AM +0300, Ville Syrjälä wrote:
> > > On Thu, May 01, 2014 at 06:47:54PM -0700, Ben Widawsky wrote:
> > > > "Restriction :
> > > > The offset must be greater than 4K bytes, avoiding the first 4KB of
> > > > stolen memory."
> > > 
> > > Isn't this a more generic issue that we must avoid the first 4k? If so
> > > I think we should just reserve the first 4k permanently at driver init
> > > time.

Is anyone opposed to this plan? Realistically it won't make a
difference.

> > 
> > What? On many machines the vga framebuffer is allocated from offset 0. I
> > think some explanation is in order.

The chopped off part of the commit message explained it (if I understood
your point).

> 
> WaSkipStolenMemoryFirstPage
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Ben Widawsky, Intel Open Source Technology Center