[Intel-gfx] [PATCH] drm/i915: Use RCS flips on Ivybridge+

[Daniel Vetter]

On Tue, Aug 20, 2013 at 10:34 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> RCS flips do work on Iybridge+ so long as we can unmask the messages
> through DERRMR. However, there are quite a few workarounds mentioned
> regarding unmasking more than one event or triggering more than one
> message through DERRMR. Those workarounds in principle prevent us from
> performing pipelined flips (and asynchronous flips across multiple
> planes) and equally apply to the "known good" BCS ring. Given that it
> already appears to work, and also appears to work with unmasking all 3
> planes at once (and queuing flips across multiple planes), be brave.
>
> Bugzlla: https://bugs.freedesktop.org/show_bug.cgi?id=67600
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Can you pls add some words with how this DERRMR write will interact
with scanline waits from SNA? I think just a few words to explain how
switching from scanline waits and blits to pageflips and back would be
good (even though I don't really expect that to happen often,
especially now that we have the buffer age extension and friends).
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch