[Intel-gfx] [PATCH 0/4] Remove useless vblank waits on Haswell

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

Hi

This series gets rid of those messages saying that the vblank wait timed out on
my Haswell machine. It saves 2 timeouts per pipe (one at mode_set, one at
crtc_enable), so it's 100ms we save per modeset.

The big idea exercised by this patch is that the pipe doesn't really start
running after we enable PIPECONF, so we had some useless waits. This idea
probably also applies to ILK/SNB/IVB and perhaps we could try to save some
vblanks on those Gens too.

I tested these patches on top of the 4 patches that fix the Haswell underruns +
the 2 IPS patches I just sent.

Thanks,
Paulo

Paulo Zanoni (4):
  drm/i915: WARN in case PIPECONF is already enabled
  drm/i915: don't intel_wait_for_vblank inside intel_enable_pipe
  drm/i915: remove useless vblank wait form haswell_crtc_enable
  drm/i915: skip useless vblank wait on Haswell audio sequence

 drivers/gpu/drm/i915/intel_display.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

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1.8.3.1