drm/i915: use _NOTRACE for gmbus/dp aux wait loops

Less clutter in the traces. And in both cases we yell rather loud
into the logs if we time out. Patch suggested by Chris Wilson.

v2: Annotate another I915_READ in dp_aux to be consistent - we filter
out all register io in wait_for and similar loops. Chris also
suggested to mark all dp_aux register access as _NOTRACE, but I think
we should keep all functionally relevant access around, and filter
unneeded bits in userspace after the trace is captured.

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ada1b31..3f633ca 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -351,7 +351,7 @@
 		}
 	}
 
-#define C (((status = I915_READ(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
+#define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
 	if (has_aux_irq)
 		done = wait_event_timeout(dev_priv->gmbus_wait_queue, C, 10);
 	else
@@ -439,7 +439,7 @@
 
 	/* Try to wait for any previous AUX channel activity */
 	for (try = 0; try < 3; try++) {
-		status = I915_READ(ch_ctl);
+		status = I915_READ_NOTRACE(ch_ctl);
 		if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
 			break;
 		msleep(1);