[Intel-gfx] [PATCH] drm/i915: Mark untiled BLT commands as fenced on gen2/3

[Daniel Vetter]

On Wed, Mar 21, 2012 at 10:48:18AM +0000, Chris Wilson wrote:
> The BLT commands on gen2/3 utilize the fence registers and so we cannot
> modify any fences for the object whilst those commands are in flight.
> Currently we marked tiled commands as occupying a fence, but forgot to
> restrict the untiled commands from preventing a fence being assigned
> before they were completed.
> 
> One side-effect is that we ten have to double check that a fence was
> allocated for a fenced buffer during move-to-active.
> 
> Reported-by: Jiri Slaby <jirislaby at gmail.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43427
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: stable at kernel.org

I've had a few comments on irc about a preliminary version of this patch,
and Chris addressed them all. So

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Futhermore I've stitched together a little testcase in i-g-t, and it
indeed blows up without this patch. So

Testcase: i-g-t/tests/gem_tiled_after_untiled_blt
Tested-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Cheers, Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48