---

yaml
---
r: 345074
b: refs/heads/master
c: b091cd9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e89861dfa3ed0d8e9d184becf25aebea14e98372
+refs/heads/master: b091cd928dfa81e8c28b9707899201358b4e50b5

trunk/drivers/gpu/drm/i915/intel_dp.c

@@ -37,6 +37,7 @@
 #include "i915_drm.h"
 #include "i915_drv.h"
 
+#define DP_RECEIVER_CAP_SIZE	0xf
 #define DP_LINK_STATUS_SIZE	6
 #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
 
@@ -1964,12 +1965,25 @@ static bool
 intel_dp_get_dpcd(struct intel_dp *intel_dp)
 {
 	if (intel_dp_aux_native_read_retry(intel_dp, 0x000, intel_dp->dpcd,
-					   sizeof(intel_dp->dpcd)) &&
-	    (intel_dp->dpcd[DP_DPCD_REV] != 0)) {
-		return true;
-	}
+					   sizeof(intel_dp->dpcd)) == 0)
+		return false; /* aux transfer failed */
 
-	return false;
+	if (intel_dp->dpcd[DP_DPCD_REV] == 0)
+		return false; /* DPCD not present */
+
+	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+	      DP_DWN_STRM_PORT_PRESENT))
+		return true; /* native DP sink */
+
+	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
+		return true; /* no per-port downstream info */
+
+	if (intel_dp_aux_native_read_retry(intel_dp, DP_DOWNSTREAM_PORT_0,
+					   intel_dp->downstream_ports,
+					   DP_MAX_DOWNSTREAM_PORTS) == 0)
+		return false; /* downstream port status fetch failed */
+
+	return true;
 }
 
 static void

trunk/drivers/gpu/drm/i915/intel_drv.h

@@ -332,6 +332,7 @@ struct intel_hdmi {
 };
 
 #define DP_RECEIVER_CAP_SIZE		0xf
+#define DP_MAX_DOWNSTREAM_PORTS		0x10
 #define DP_LINK_CONFIGURATION_SIZE	9
 
 struct intel_dp {
@@ -346,6 +347,7 @@ struct intel_dp {
 	uint8_t link_bw;
 	uint8_t lane_count;
 	uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
+	uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
 	struct i2c_adapter adapter;
 	struct i2c_algo_dp_aux_data algo;
 	bool is_pch_edp;