drm/i915 invalidate indirect state pointers at end of ring exec

This is required by the spec, and without this some 3D programs will
hang after resume from RC6 we enable that.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_dma.c

@@ -499,6 +499,13 @@ static int i915_dispatch_batchbuffer(struct drm_device * dev,
 		}
 	}
 
+
+	if (IS_G4X(dev) || IS_IRONLAKE(dev)) {
+		BEGIN_LP_RING(2);
+		OUT_RING(MI_FLUSH | MI_NO_WRITE_FLUSH | MI_INVALIDATE_ISP);
+		OUT_RING(MI_NOOP);
+		ADVANCE_LP_RING();
+	}
 	i915_emit_breadcrumb(dev);
 
 	return 0;

drivers/gpu/drm/i915/i915_reg.h

@@ -170,6 +170,7 @@
 #define   MI_NO_WRITE_FLUSH	(1 << 2)
 #define   MI_SCENE_COUNT	(1 << 3) /* just increment scene count */
 #define   MI_END_SCENE		(1 << 4) /* flush binner and incr scene count */
+#define   MI_INVALIDATE_ISP	(1 << 5) /* invalidate indirect state pointers */
 #define MI_BATCH_BUFFER_END	MI_INSTR(0x0a, 0)
 #define MI_REPORT_HEAD		MI_INSTR(0x07, 0)
 #define MI_OVERLAY_FLIP		MI_INSTR(0x11,0)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -535,7 +535,16 @@ render_ring_dispatch_gem_execbuffer(struct drm_device *dev,
 		intel_ring_advance(dev, ring);
 	}
 
+	if (IS_G4X(dev) || IS_IRONLAKE(dev)) {
+		intel_ring_begin(dev, ring, 2);
+		intel_ring_emit(dev, ring, MI_FLUSH |
+				MI_NO_WRITE_FLUSH |
+				MI_INVALIDATE_ISP );
+		intel_ring_emit(dev, ring, MI_NOOP);
+		intel_ring_advance(dev, ring);
+	}
 	/* XXX breadcrumb */
+
 	return 0;
 }