drm/i915: Stop using RP_DOWN_EI on Baytrail

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On Baytrail, we manually calculate busyness over the evaluation interval
to avoid issues with miscaluations with RC6 enabled. However, it turns
out that the DOWN_EI interrupt generator is completely bust - it
operates in two modes, continuous or never. Neither of which are
conducive to good behaviour. Stop unmask the DOWN_EI interrupt and just
compute everything from the UP_EI which does seem to correspond to the
desired interval.

v2: Fixup gen6_rps_pm_mask() as well
v3: Inline vlv_c0_above() to combine the now identical elapsed
calculation for up/down and simplify the threshold testing

Fixes: 43cf3bf084 ("drm/i915: Improved w/a for rps on Baytrail")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.1+
Link: http://patchwork.freedesktop.org/patch/msgid/20170309211232.28878-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313170617.31564-1-chris@chris-wilson.co.uk
(cherry picked from commit e0e8c7cb6e)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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This commit is contained in:

Chris Wilson 2017-03-13 17:06:17 +00:00 • committed by Jani Nikula

parent 0f5418e564

commit 8f68d591d4

3 changed files with 32 additions and 48 deletions

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2

drivers/gpu/drm/i915/i915_drv.h

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75

drivers/gpu/drm/i915/i915_irq.c

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5

drivers/gpu/drm/i915/intel_pm.c

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