drm/i915/ringbuffer: Fix emit batch buffer regression from 8187a2b

In commit 8187a2b, the number of dwords used in the ringbuffer for
executing the batch buffer was erroneously changed from 2 to 4.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 89004a6..f1e0538 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -476,7 +476,7 @@ render_ring_dispatch_gem_execbuffer(struct drm_device *dev,
                        intel_ring_emit(dev, ring, exec_start + exec_len - 4);
                        intel_ring_emit(dev, ring, 0);
                } else {
-                       intel_ring_begin(dev, ring, 4);
+                       intel_ring_begin(dev, ring, 2);
                        if (INTEL_INFO(dev)->gen >= 4) {
                                intel_ring_emit(dev, ring,
                                                MI_BATCH_BUFFER_START | (2 << 6)