---

yaml
---
r: 253721
b: refs/heads/master
c: 4a9a8b7
h: refs/heads/master
i:
  253719: 4bb8047
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f49dadb82dde88092827b6d058e7164e75e96759
+refs/heads/master: 4a9a8b71e12d41abb71c4e741bff524f016cfef4

trunk/drivers/gpu/drm/drm_edid.c

@@ -258,6 +258,17 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
 	return ret == 2 ? 0 : -1;
 }
 
+static bool drm_edid_is_zero(u8 *in_edid, int length)
+{
+	int i;
+	u32 *raw_edid = (u32 *)in_edid;
+
+	for (i = 0; i < length / 4; i++)
+		if (*(raw_edid + i) != 0)
+			return false;
+	return true;
+}
+
 static u8 *
 drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
 {
@@ -273,6 +284,10 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
 			goto out;
 		if (drm_edid_block_valid(block))
 			break;
+		if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
+			connector->null_edid_counter++;
+			goto carp;
+		}
 	}
 	if (i == 4)
 		goto carp;

trunk/drivers/gpu/drm/radeon/radeon_connectors.c

@@ -836,6 +836,13 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
 		if (!radeon_connector->edid) {
 			DRM_ERROR("%s: probed a monitor but no|invalid EDID\n",
 					drm_get_connector_name(connector));
+			/* rs690 seems to have a problem with connectors not existing and always
+			 * return a block of 0's. If we see this just stop polling on this output */
+			if ((rdev->family == CHIP_RS690 || rdev->family == CHIP_RS740) && radeon_connector->base.null_edid_counter) {
+				ret = connector_status_disconnected;
+				DRM_ERROR("%s: detected RS690 floating bus bug, stopping ddc detect\n", drm_get_connector_name(connector));
+				radeon_connector->ddc_bus = NULL;
+			}
 		} else {
 			radeon_connector->use_digital = !!(radeon_connector->edid->input & DRM_EDID_INPUT_DIGITAL);
 

trunk/include/drm/drm_crtc.h

@@ -520,6 +520,8 @@ struct drm_connector {
 	uint32_t encoder_ids[DRM_CONNECTOR_MAX_ENCODER];
 	uint32_t force_encoder_id;
 	struct drm_encoder *encoder; /* currently active encoder */
+
+	int null_edid_counter; /* needed to workaround some HW bugs where we get all 0s */
 };
 
 /**