PIPE_DPST_EVENT_ENABLE  529 drivers/gpu/drm/gma500/psb_intel_reg.h #define PIPE_DPST_EVENT_ENABLE			(1UL << 23)
PIPE_DPST_EVENT_ENABLE 5689 drivers/gpu/drm/i915/i915_reg.h #define   PIPE_DPST_EVENT_ENABLE		(1UL << 23)