drm/i915: Always update RPS interrupts thresholds along with frequency
authorChris Wilson <chris@chris-wilson.co.uk>
Sat, 28 Apr 2012 07:56:39 +0000 (08:56 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 24 May 2012 15:54:00 +0000 (17:54 +0200)
commit7b9e0ae6da0a7eaf2680a1a788f08df123724f3b
tree34098c8670c181ac16210d7647057cbc22ceb6f1
parent59d92bfa5f0cdf57f82f5181b0ad6af75c3fdf41
drm/i915: Always update RPS interrupts thresholds along with frequency

In order to avoid missed down-interrupts when coming out of RC6, it is
advised that we always reset the down-threshold upon a PM event. This is
due to that the PM unit goes through a little dance when coming out of
RC6, it first brings the GPU up at the lowest frequency then a short
time later it restores the thresholds. During that interval, the
down-interval may expire and the interrupt be suppressed.

Now aware of the dance taking place within the GPU when coming out of
RC6, one wonders what other writes need to be queued in the fifo buffer
in order to be properly sequenced; setting the RP state appears to be
one.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44006
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_irq.c
drivers/gpu/drm/i915/intel_pm.c