drm/i915/bdw: Use HSW formula for ring freq scaling
authorBen Widawsky <benjamin.widawsky@intel.com>
Sun, 3 Nov 2013 04:07:49 +0000 (21:07 -0700)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Fri, 8 Nov 2013 17:10:00 +0000 (18:10 +0100)
commit46c764d41f54ca9f03c50b5d7845bc97ac46c11a
tree77867779e99021b84fc3ee5f6dc0a8742c0fe5ac
parented8546ac1f99b850879f07b1e9b06b42fb0a36d9
drm/i915/bdw: Use HSW formula for ring freq scaling

The current formula we use for HSW is not what is in current docs.
However, changing to the HSW formula on my HSW does not improve power
usage, and decreases performance by about 5% in limited xonotic testing.

For gen8, until we know otherwise, or run experiments, let's use
the HSW formula - which should be the same used in the Windows driver
(and thus help make an apples-applies comparison) on gen8.

v2: Use >= 8 instead of > 7 to be consistent with all other gen
checks.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_pm.c