drm/i915: Don't emit mbox updates without semaphores

Aside from the fact that it leaves confusing dumps on error capture, it
is entirely unnecessary, and potentially harmful in cases like BDW,
where the instruction has changed.

In reality (seemingly), this will have no behavioral impact.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ben Widawsky 2013-12-16 20:50:38 -08:00 committed by Daniel Vetter
parent 0e79284d13
commit 52ed23253b

View File

@ -663,14 +663,15 @@ gen6_add_request(struct intel_ring_buffer *ring)
struct drm_device *dev = ring->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_ring_buffer *useless;
int i, ret;
int i, ret, num_dwords = 4;
ret = intel_ring_begin(ring, ((I915_NUM_RINGS-1) *
MBOX_UPDATE_DWORDS) +
4);
if (i915_semaphore_is_enabled(dev))
num_dwords += ((I915_NUM_RINGS-1) * MBOX_UPDATE_DWORDS);
#undef MBOX_UPDATE_DWORDS
ret = intel_ring_begin(ring, num_dwords);
if (ret)
return ret;
#undef MBOX_UPDATE_DWORDS
for_each_ring(useless, dev_priv, i) {
u32 mbox_reg = ring->signal_mbox[i];