drm/i915: Rely on TEST_SINK_START instead of tracking Sink CRC state on dev_priv.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@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 948a7b0..6c17b0b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3985,7 +3985,6 @@
 		ret = -ETIMEDOUT;
 	}
 
-	intel_dp->sink_crc.started = false;
  out:
 	hsw_enable_ips(intel_crtc);
 	return ret;
@@ -3999,12 +3998,6 @@
 	u8 buf;
 	int ret;
 
-	if (intel_dp->sink_crc.started) {
-		ret = intel_dp_sink_crc_stop(intel_dp);
-		if (ret)
-			return ret;
-	}
-
 	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf) < 0)
 		return -EIO;
 
@@ -4014,6 +4007,12 @@
 	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0)
 		return -EIO;
 
+	if (buf & DP_TEST_SINK_START) {
+		ret = intel_dp_sink_crc_stop(intel_dp);
+		if (ret)
+			return ret;
+	}
+
 	hsw_disable_ips(intel_crtc);
 
 	if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
@@ -4023,7 +4022,6 @@
 	}
 
 	intel_wait_for_vblank(dev, intel_crtc->pipe);
-	intel_dp->sink_crc.started = true;
 	return 0;
 }