drm/i915: Extend vlv/chv residency resolution
authorMika Kuoppala <mika.kuoppala@linux.intel.com>
Wed, 15 Mar 2017 16:07:13 +0000 (18:07 +0200)
committerMika Kuoppala <mika.kuoppala@intel.com>
Thu, 16 Mar 2017 10:28:28 +0000 (12:28 +0200)
commit47c21d9a1a7b4b3177dde686ce0eb71cdf25e07b
treefc51595627946c7fbdbe0009d5a2c1950d9d2a93
parentc5a0ad114b6a9f4ad03f30bd7c61994bc6e8ab52
drm/i915: Extend vlv/chv residency resolution

Vlv and chv residency counters are 40 bits in width.
With a control bit, we can choose between upper or lower
32 bit window into this counter.

Lets toggle this bit on and off on and read both parts.
As a result we can push the wrap from 13 seconds to 54
minutes.

v2: commit msg, loop readability, goto elimination (Chris)
v3: bug ref, divide outside runtime pm lock (Chris)

References: https://bugs.freedesktop.org/show_bug.cgi?id=94852
Reported-by: Len Brown <len.brown@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
drivers/gpu/drm/i915/intel_pm.c