[Intel-gfx] [PATCH] drm/i915:: Disable FBC on SandyBridge

[Chris Wilson]

On Tue, 17 Jan 2012 11:57:05 +0100, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Tue, Nov 08, 2011 at 11:17:34PM +0000, Chris Wilson wrote:
> > Enabling FBC is causing the BLT ring to run between 10-100x slower than
> > normal and frequently lockup. The interim solution is disable FBC once
> > more until we know why.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> Iirc fbc isn't really worth it power-wise on snb and we don't implement it on
> ivb. So shouldn't we just disable it completely? Eugeni, any opinions - I
> think you're most up to speed on power saving figures for snb?

Also note that I've had a couple of people confirm this bug and tested
the patch on IRC. Doesn't help explain precisely what is wrong nor if
there is a better workaround amidst the chicken bits that we've missed.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre