drm/i915: Don't wait for Punit after each freq change on VLV
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 25 Jun 2013 16:21:02 +0000 (19:21 +0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 1 Jul 2013 09:14:48 +0000 (11:14 +0200)
commit80814ae4dae5d2070b1ca848df728feb6a10e6f2
tree615107a6b7a14ca91c4cab3e19b6a8084f6dfe60
parent73008b989faf4200907a858f9b902ee29d6edbea
drm/i915: Don't wait for Punit after each freq change on VLV

It seems that even though Punit reports the frequency change to have
been completed, it still reports the old frequency in the status
register for some time.

So rather than polling for Punit to complete the frequency change after
each request, poll before. This gets rid of the spurious "Punit overrode
GPU freq" messages.

This also lets us continue working while Punit is performing the actual
frequency change. As a result, openarena demo088-test1 timedemo average
fps is increased by ~5 fps, and the slowest frame duration is reduced
by ~25%.

The sysfs cur_freq file always reads the current frequency from Punit
anyway, so having rps.cur_delay be slightly off at times doesn't matter.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_pm.c