drm/i915: Enable interrupt-based AGPBUSY# enable on 85x
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 25 Feb 2014 13:13:40 +0000 (15:13 +0200)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 5 Jun 2014 06:52:39 +0000 (08:52 +0200)
commit54e472ae9632992bfbd0c6fd8c8fc5c88d2bdd1f
treeaa99d6db0d20ed0b6659be7e4abadd91511b8b7e
parent3299254ffc42082a0ae36ecb841ade1a98a2af92
drm/i915: Enable interrupt-based AGPBUSY# enable on 85x

85x also has a similar AGPBUSY# bit as gen3. Enable it to make
sure vblank interrupts don't get dealyed during C3 state.

There's also another bit which controls whether AGPBUSY# is asserted
based on pending cacheable cycles and interrupts, or just based on
pending commands in the ring and interrupts. Select the cacheable
cycles mode since that seems to be the new way of doing things in
85x, and it does give slightly better C3 residency numbers with
glxgears running.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_pm.c