drm/i915: Force sync command ordering (Gen6+)

The docs say this is required for Gen7, and since the bit was added for
Gen6, we are also setting it there pit pf paranoia. Particularly as
Chris points out, if PIPE_CONTROL counts as a 3d state packet.

This was found through doc inspection by Ken and applies to Gen6+;

Reported-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ca70e2f10445..f5dae5deca71 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -414,6 +414,11 @@ static int init_render_ring(struct intel_ring_buffer *ring)
                         return ret;
         }
 
+        if (INTEL_INFO(dev)->gen >= 6) {
+                I915_WRITE(INSTPM,
+                           INSTPM_FORCE_ORDERING << 16 | INSTPM_FORCE_ORDERING);
+        }
+
         return ret;
 }