[Intel-gfx] [PATCH 6/6] drm/i915: Really wait for pending flips in intel_pipe_set_base()

[Daniel Vetter]

On Wed, Feb 13, 2013 at 6:26 PM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> The flip is making progress on the GPU side, and at the same time the
> CPU side can make some progress with the pin operation. At least that
> was my theory.

The pin should be a no-op when moving a given framebuffer around. It's
only really expensive when we need to clflush (and lesser so when we
need to rewrite ptes), which should only happen on fresh framebuffers.
As long as userspace does it's job and caches scanout buffers we
should be fine. The other thing is waiting for outstanding rendering
(to avoid hanging on an MI_WAIT_SCANLINE cmd), which just blocks. So
doesn't really matter imo.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch