The docs are not very clear on exactly what this means. Another doc however mentioned that [not] enabling this can significantly increase consumption impact.
Some early tests show no perf regression in Nexuiz, but a fairly significant regression in OA (252FPS -> 240FPS). Unfortunately I do not have a good setup to check if it actually helps with power. CC: Daniel Vetter <[email protected]> Signed-off-by: Ben Widawsky <[email protected]> --- drivers/gpu/drm/i915/i915_dma.c | 5 +++++ drivers/gpu/drm/i915/i915_reg.h | 3 +++ 2 files changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 333b746..7358be8 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1218,6 +1218,11 @@ static int i915_load_gem_init(struct drm_device *dev) drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size); mutex_lock(&dev->struct_mutex); + + if (i915_powersave && IS_IVYBRIDGE(dev)) + I915_WRITE(GEN7_MISCCPCTL, + I915_READ(GEN7_MISCCPCTL) | GEN7_DOP_CLOCK_GATE_ENABLE); + if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) { /* PPGTT pdes are stolen from global gtt ptes, so shrink the * aperture accordingly when using aliasing ppgtt. */ diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 972321f..db0b480 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3991,6 +3991,9 @@ #define GEN6_RC6 3 #define GEN6_RC7 4 +#define GEN7_MISCCPCTL 0x9424 +#define GEN7_DOP_CLOCK_GATE_ENABLE (1<<0) + #define G4X_AUD_VID_DID 0x62020 #define INTEL_AUDIO_DEVCL 0x808629FB #define INTEL_AUDIO_DEVBLC 0x80862801 -- 1.7.10 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
