drm/i915: Enable RC6 on Ironlake.

RC6 allows the GPU to enter a lower power state when the GPU is idle.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
[anholt: Fixed the !renderctx error path to actually not enable RC6.]
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4668e9bf67d8..149c18b7c375 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5753,7 +5753,8 @@ void intel_init_clock_gating(struct drm_device *dev)
                                    ILK_DPFC_DIS2 |
                                    ILK_CLK_FBC);
                 }
-                return;
+                if (IS_GEN6(dev))
+                        return;
         } else if (IS_G4X(dev)) {
                 uint32_t dspclk_gate;
                 I915_WRITE(RENCLK_GATE_D1, 0);
@@ -5814,9 +5815,11 @@ void intel_init_clock_gating(struct drm_device *dev)
                                 OUT_RING(MI_FLUSH);
                                 ADVANCE_LP_RING();
                         }
-                } else
+                } else {
                         DRM_DEBUG_KMS("Failed to allocate render context."
-                                       "Disable RC6\n");
+                                      "Disable RC6\n");
+                        return;
+                }
         }
 
         if (I915_HAS_RC6(dev) && drm_core_check_feature(dev, DRIVER_MODESET)) {