Merge branch 'drm-mst-next' of ssh://people.freedesktop.org/~/linux into drm-next

Merge mst tiling patches and MST fixes

* 'drm-mst-next' of ssh://people.freedesktop.org/~/linux:
  drm/fb: add support for tiled monitor configurations. (v2)
  drm/tile: expose the tile property to userspace (v3)
  drm/connector: store tile information from displayid (v3)
  drm/mst: cached EDID for logical ports (v2)
  drm: add tile_group support. (v3)
  drm/displayid: add displayid defines and edid extension (v2)
  drm/dp-mst: Remove branches before dropping the reference
  drm/fb_helper: move deferred fb checking into restore mode (v2)
  drm/dp: retry AUX transactions 32 times (v1.1)

Documentation/DocBook/drm.tmpl

@@ -2412,6 +2412,10 @@ void intel_crt_init(struct drm_device *dev)
 !Edrivers/gpu/drm/drm_plane_helper.c
 !Pdrivers/gpu/drm/drm_plane_helper.c overview
     </sect2>
+    <sect2>
+	  <title>Tile group</title>
+!Pdrivers/gpu/drm/drm_crtc.c Tile group
+    </sect2>
   </sect1>
 
   <!-- Internals: kms properties -->
@@ -2547,7 +2551,7 @@ void intel_crt_init(struct drm_device *dev)
 	</tr>
 	<tr>
 	<td rowspan="23" valign="top" >DRM</td>
-	<td rowspan="3" valign="top" >Generic</td>
+	<td rowspan="4" valign="top" >Generic</td>
 	<td valign="top" >“EDID”</td>
 	<td valign="top" >BLOB | IMMUTABLE</td>
 	<td valign="top" >0</td>
@@ -2569,6 +2573,13 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >Contains topology path to a connector.</td>
 	</tr>
 	<tr>
+	<td valign="top" >“TILE”</td>
+	<td valign="top" >BLOB | IMMUTABLE</td>
+	<td valign="top" >0</td>
+	<td valign="top" >Connector</td>
+	<td valign="top" >Contains tiling information for a connector.</td>
+	</tr>
+	<tr>
 	<td rowspan="1" valign="top" >Plane</td>
 	<td valign="top" >“type”</td>
 	<td valign="top" >ENUM | IMMUTABLE</td>

drivers/gpu/drm/drm_crtc.c

@@ -908,6 +908,11 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	struct drm_device *dev = connector->dev;
 	struct drm_display_mode *mode, *t;
 
+	if (connector->tile_group) {
+		drm_mode_put_tile_group(dev, connector->tile_group);
+		connector->tile_group = NULL;
+	}
+
 	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
 		drm_mode_remove(connector, mode);
 
@@ -1339,6 +1344,11 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
 				       "PATH", 0);
 	dev->mode_config.path_property = dev_path;
 
+	dev->mode_config.tile_property = drm_property_create(dev,
+							     DRM_MODE_PROP_BLOB |
+							     DRM_MODE_PROP_IMMUTABLE,
+							     "TILE", 0);
+
 	return 0;
 }
 
@@ -4082,6 +4092,52 @@ int drm_mode_connector_set_path_property(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_mode_connector_set_path_property);
 
+/**
+ * drm_mode_connector_set_tile_property - set tile property on connector
+ * @connector: connector to set property on.
+ *
+ * This looks up the tile information for a connector, and creates a
+ * property for userspace to parse if it exists. The property is of
+ * the form of 8 integers using ':' as a separator.
+ *
+ * Returns:
+ * Zero on success, errno on failure.
+ */
+int drm_mode_connector_set_tile_property(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	int ret, size;
+	char tile[256];
+
+	if (connector->tile_blob_ptr)
+		drm_property_destroy_blob(dev, connector->tile_blob_ptr);
+
+	if (!connector->has_tile) {
+		connector->tile_blob_ptr = NULL;
+		ret = drm_object_property_set_value(&connector->base,
+						    dev->mode_config.tile_property, 0);
+		return ret;
+	}
+
+	snprintf(tile, 256, "%d:%d:%d:%d:%d:%d:%d:%d",
+		 connector->tile_group->id, connector->tile_is_single_monitor,
+		 connector->num_h_tile, connector->num_v_tile,
+		 connector->tile_h_loc, connector->tile_v_loc,
+		 connector->tile_h_size, connector->tile_v_size);
+	size = strlen(tile) + 1;
+
+	connector->tile_blob_ptr = drm_property_create_blob(connector->dev,
+							    size, tile);
+	if (!connector->tile_blob_ptr)
+		return -EINVAL;
+
+	ret = drm_object_property_set_value(&connector->base,
+					    dev->mode_config.tile_property,
+					    connector->tile_blob_ptr->base.id);
+	return ret;
+}
+EXPORT_SYMBOL(drm_mode_connector_set_tile_property);
+
 /**
  * drm_mode_connector_update_edid_property - update the edid property of a connector
  * @connector: drm connector
@@ -5152,6 +5208,7 @@ void drm_mode_config_init(struct drm_device *dev)
 	INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
 	INIT_LIST_HEAD(&dev->mode_config.plane_list);
 	idr_init(&dev->mode_config.crtc_idr);
+	idr_init(&dev->mode_config.tile_idr);
 
 	drm_modeset_lock_all(dev);
 	drm_mode_create_standard_connector_properties(dev);
@@ -5239,6 +5296,7 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 		crtc->funcs->destroy(crtc);
 	}
 
+	idr_destroy(&dev->mode_config.tile_idr);
 	idr_destroy(&dev->mode_config.crtc_idr);
 	drm_modeset_lock_fini(&dev->mode_config.connection_mutex);
 }
@@ -5261,3 +5319,100 @@ struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 					   supported_rotations);
 }
 EXPORT_SYMBOL(drm_mode_create_rotation_property);
+
+/**
+ * DOC: Tile group
+ *
+ * Tile groups are used to represent tiled monitors with a unique
+ * integer identifier. Tiled monitors using DisplayID v1.3 have
+ * a unique 8-byte handle, we store this in a tile group, so we
+ * have a common identifier for all tiles in a monitor group.
+ */
+static void drm_tile_group_free(struct kref *kref)
+{
+	struct drm_tile_group *tg = container_of(kref, struct drm_tile_group, refcount);
+	struct drm_device *dev = tg->dev;
+	mutex_lock(&dev->mode_config.idr_mutex);
+	idr_remove(&dev->mode_config.tile_idr, tg->id);
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	kfree(tg);
+}
+
+/**
+ * drm_mode_put_tile_group - drop a reference to a tile group.
+ * @dev: DRM device
+ * @tg: tile group to drop reference to.
+ *
+ * drop reference to tile group and free if 0.
+ */
+void drm_mode_put_tile_group(struct drm_device *dev,
+			     struct drm_tile_group *tg)
+{
+	kref_put(&tg->refcount, drm_tile_group_free);
+}
+
+/**
+ * drm_mode_get_tile_group - get a reference to an existing tile group
+ * @dev: DRM device
+ * @topology: 8-bytes unique per monitor.
+ *
+ * Use the unique bytes to get a reference to an existing tile group.
+ *
+ * RETURNS:
+ * tile group or NULL if not found.
+ */
+struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
+					       char topology[8])
+{
+	struct drm_tile_group *tg;
+	int id;
+	mutex_lock(&dev->mode_config.idr_mutex);
+	idr_for_each_entry(&dev->mode_config.tile_idr, tg, id) {
+		if (!memcmp(tg->group_data, topology, 8)) {
+			if (!kref_get_unless_zero(&tg->refcount))
+				tg = NULL;
+			mutex_unlock(&dev->mode_config.idr_mutex);
+			return tg;
+		}
+	}
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	return NULL;
+}
+
+/**
+ * drm_mode_create_tile_group - create a tile group from a displayid description
+ * @dev: DRM device
+ * @topology: 8-bytes unique per monitor.
+ *
+ * Create a tile group for the unique monitor, and get a unique
+ * identifier for the tile group.
+ *
+ * RETURNS:
+ * new tile group or error.
+ */
+struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
+						  char topology[8])
+{
+	struct drm_tile_group *tg;
+	int ret;
+
+	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
+	if (!tg)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&tg->refcount);
+	memcpy(tg->group_data, topology, 8);
+	tg->dev = dev;
+
+	mutex_lock(&dev->mode_config.idr_mutex);
+	ret = idr_alloc(&dev->mode_config.tile_idr, tg, 1, 0, GFP_KERNEL);
+	if (ret >= 0) {
+		tg->id = ret;
+	} else {
+		kfree(tg);
+		tg = ERR_PTR(ret);
+	}
+
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	return tg;
+}

drivers/gpu/drm/drm_dp_helper.c

@@ -186,10 +186,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
 
 	/*
 	 * The specification doesn't give any recommendation on how often to
-	 * retry native transactions, so retry 7 times like for I2C-over-AUX
-	 * transactions.
+	 * retry native transactions. We used to retry 7 times like for
+	 * aux i2c transactions but real world devices this wasn't
+	 * sufficient, bump to 32 which makes Dell 4k monitors happier.
 	 */
-	for (retry = 0; retry < 7; retry++) {
+	for (retry = 0; retry < 32; retry++) {
 
 		mutex_lock(&aux->hw_mutex);
 		err = aux->transfer(aux, &msg);

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -839,6 +839,8 @@ static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 
 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 {
+	struct drm_dp_mst_branch *mstb;
+
 	switch (old_pdt) {
 	case DP_PEER_DEVICE_DP_LEGACY_CONV:
 	case DP_PEER_DEVICE_SST_SINK:
@@ -846,8 +848,9 @@ static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 		drm_dp_mst_unregister_i2c_bus(&port->aux);
 		break;
 	case DP_PEER_DEVICE_MST_BRANCHING:
-		drm_dp_put_mst_branch_device(port->mstb);
+		mstb = port->mstb;
 		port->mstb = NULL;
+		drm_dp_put_mst_branch_device(mstb);
 		break;
 	}
 }
@@ -858,6 +861,8 @@ static void drm_dp_destroy_port(struct kref *kref)
 	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 	if (!port->input) {
 		port->vcpi.num_slots = 0;
+
+		kfree(port->cached_edid);
 		if (port->connector)
 			(*port->mgr->cbs->destroy_connector)(mgr, port->connector);
 		drm_dp_port_teardown_pdt(port, port->pdt);
@@ -1097,6 +1102,10 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
 		char proppath[255];
 		build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
 		port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
+
+		if (port->port_num >= 8) {
+			port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
+		}
 	}
 
 	/* put reference to this port */
@@ -2167,7 +2176,8 @@ EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
  * This returns the current connection state for a port. It validates the
  * port pointer still exists so the caller doesn't require a reference
  */
-enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
+						 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 {
 	enum drm_connector_status status = connector_status_disconnected;
 
@@ -2186,6 +2196,10 @@ enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr
 
 	case DP_PEER_DEVICE_SST_SINK:
 		status = connector_status_connected;
+		/* for logical ports - cache the EDID */
+		if (port->port_num >= 8 && !port->cached_edid) {
+			port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
+		}
 		break;
 	case DP_PEER_DEVICE_DP_LEGACY_CONV:
 		if (port->ldps)
@@ -2217,7 +2231,12 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_
 	if (!port)
 		return NULL;
 
-	edid = drm_get_edid(connector, &port->aux.ddc);
+	if (port->cached_edid)
+		edid = drm_edid_duplicate(port->cached_edid);
+	else
+		edid = drm_get_edid(connector, &port->aux.ddc);
+
+	drm_mode_connector_set_tile_property(connector);
 	drm_dp_put_port(port);
 	return edid;
 }

drivers/gpu/drm/drm_edid.c

@@ -34,6 +34,7 @@
 #include <linux/module.h>
 #include <drm/drmP.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_displayid.h>
 
 #define version_greater(edid, maj, min) \
 	(((edid)->version > (maj)) || \
@@ -1014,6 +1015,8 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
 MODULE_PARM_DESC(edid_fixup,
 		 "Minimum number of valid EDID header bytes (0-8, default 6)");
 
+static void drm_get_displayid(struct drm_connector *connector,
+			      struct edid *edid);
 /**
  * drm_edid_block_valid - Sanity check the EDID block (base or extension)
  * @raw_edid: pointer to raw EDID block
@@ -1308,10 +1311,15 @@ EXPORT_SYMBOL(drm_probe_ddc);
 struct edid *drm_get_edid(struct drm_connector *connector,
 			  struct i2c_adapter *adapter)
 {
+	struct edid *edid;
+
 	if (!drm_probe_ddc(adapter))
 		return NULL;
 
-	return drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
+	edid = drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
+	if (edid)
+		drm_get_displayid(connector, edid);
+	return edid;
 }
 EXPORT_SYMBOL(drm_get_edid);
 
@@ -2406,7 +2414,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 /*
  * Search EDID for CEA extension block.
  */
-static u8 *drm_find_cea_extension(struct edid *edid)
+static u8 *drm_find_edid_extension(struct edid *edid, int ext_id)
 {
 	u8 *edid_ext = NULL;
 	int i;
@@ -2418,7 +2426,7 @@ static u8 *drm_find_cea_extension(struct edid *edid)
 	/* Find CEA extension */
 	for (i = 0; i < edid->extensions; i++) {
 		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
-		if (edid_ext[0] == CEA_EXT)
+		if (edid_ext[0] == ext_id)
 			break;
 	}
 
@@ -2428,6 +2436,16 @@ static u8 *drm_find_cea_extension(struct edid *edid)
 	return edid_ext;
 }
 
+static u8 *drm_find_cea_extension(struct edid *edid)
+{
+	return drm_find_edid_extension(edid, CEA_EXT);
+}
+
+static u8 *drm_find_displayid_extension(struct edid *edid)
+{
+	return drm_find_edid_extension(edid, DISPLAYID_EXT);
+}
+
 /*
  * Calculate the alternate clock for the CEA mode
  * (60Hz vs. 59.94Hz etc.)
@@ -3888,3 +3906,123 @@ drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
 	return 0;
 }
 EXPORT_SYMBOL(drm_hdmi_vendor_infoframe_from_display_mode);
+
+static int drm_parse_display_id(struct drm_connector *connector,
+				u8 *displayid, int length,
+				bool is_edid_extension)
+{
+	/* if this is an EDID extension the first byte will be 0x70 */
+	int idx = 0;
+	struct displayid_hdr *base;
+	struct displayid_block *block;
+	u8 csum = 0;
+	int i;
+
+	if (is_edid_extension)
+		idx = 1;
+
+	base = (struct displayid_hdr *)&displayid[idx];
+
+	DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
+		      base->rev, base->bytes, base->prod_id, base->ext_count);
+
+	if (base->bytes + 5 > length - idx)
+		return -EINVAL;
+
+	for (i = idx; i <= base->bytes + 5; i++) {
+		csum += displayid[i];
+	}
+	if (csum) {
+		DRM_ERROR("DisplayID checksum invalid, remainder is %d\n", csum);
+		return -EINVAL;
+	}
+
+	block = (struct displayid_block *)&displayid[idx + 4];
+	DRM_DEBUG_KMS("block id %d, rev %d, len %d\n",
+		      block->tag, block->rev, block->num_bytes);
+
+	switch (block->tag) {
+	case DATA_BLOCK_TILED_DISPLAY: {
+		struct displayid_tiled_block *tile = (struct displayid_tiled_block *)block;
+
+		u16 w, h;
+		u8 tile_v_loc, tile_h_loc;
+		u8 num_v_tile, num_h_tile;
+		struct drm_tile_group *tg;
+
+		w = tile->tile_size[0] | tile->tile_size[1] << 8;
+		h = tile->tile_size[2] | tile->tile_size[3] << 8;
+
+		num_v_tile = (tile->topo[0] & 0xf) | (tile->topo[2] & 0x30);
+		num_h_tile = (tile->topo[0] >> 4) | ((tile->topo[2] >> 2) & 0x30);
+		tile_v_loc = (tile->topo[1] & 0xf) | ((tile->topo[2] & 0x3) << 4);
+		tile_h_loc = (tile->topo[1] >> 4) | (((tile->topo[2] >> 2) & 0x3) << 4);
+
+		connector->has_tile = true;
+		if (tile->tile_cap & 0x80)
+			connector->tile_is_single_monitor = true;
+
+		connector->num_h_tile = num_h_tile + 1;
+		connector->num_v_tile = num_v_tile + 1;
+		connector->tile_h_loc = tile_h_loc;
+		connector->tile_v_loc = tile_v_loc;
+		connector->tile_h_size = w + 1;
+		connector->tile_v_size = h + 1;
+
+		DRM_DEBUG_KMS("tile cap 0x%x\n", tile->tile_cap);
+		DRM_DEBUG_KMS("tile_size %d x %d\n", w + 1, h + 1);
+		DRM_DEBUG_KMS("topo num tiles %dx%d, location %dx%d\n",
+		       num_h_tile + 1, num_v_tile + 1, tile_h_loc, tile_v_loc);
+		DRM_DEBUG_KMS("vend %c%c%c\n", tile->topology_id[0], tile->topology_id[1], tile->topology_id[2]);
+
+		tg = drm_mode_get_tile_group(connector->dev, tile->topology_id);
+		if (!tg) {
+			tg = drm_mode_create_tile_group(connector->dev, tile->topology_id);
+		}
+		if (!tg)
+			return -ENOMEM;
+
+		if (connector->tile_group != tg) {
+			/* if we haven't got a pointer,
+			   take the reference, drop ref to old tile group */
+			if (connector->tile_group) {
+				drm_mode_put_tile_group(connector->dev, connector->tile_group);
+			}
+			connector->tile_group = tg;
+		} else
+			/* if same tile group, then release the ref we just took. */
+			drm_mode_put_tile_group(connector->dev, tg);
+	}
+		break;
+	default:
+		printk("unknown displayid tag %d\n", block->tag);
+		break;
+	}
+	return 0;
+}
+
+static void drm_get_displayid(struct drm_connector *connector,
+			      struct edid *edid)
+{
+	void *displayid = NULL;
+	int ret;
+	connector->has_tile = false;
+	displayid = drm_find_displayid_extension(edid);
+	if (!displayid) {
+		/* drop reference to any tile group we had */
+		goto out_drop_ref;
+	}
+
+	ret = drm_parse_display_id(connector, displayid, EDID_LENGTH, true);
+	if (ret < 0)
+		goto out_drop_ref;
+	if (!connector->has_tile)
+		goto out_drop_ref;
+	return;
+out_drop_ref:
+	if (connector->tile_group) {
+		drm_mode_put_tile_group(connector->dev, connector->tile_group);
+		connector->tile_group = NULL;
+	}
+	return;
+}

drivers/gpu/drm/drm_fb_helper.c

@@ -347,9 +347,18 @@ bool drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 {
 	struct drm_device *dev = fb_helper->dev;
 	bool ret;
+	bool do_delayed = false;
+
 	drm_modeset_lock_all(dev);
 	ret = restore_fbdev_mode(fb_helper);
+
+	do_delayed = fb_helper->delayed_hotplug;
+	if (do_delayed)
+		fb_helper->delayed_hotplug = false;
 	drm_modeset_unlock_all(dev);
+
+	if (do_delayed)
+		drm_fb_helper_hotplug_event(fb_helper);
 	return ret;
 }
 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
@@ -888,10 +897,6 @@ int drm_fb_helper_set_par(struct fb_info *info)
 
 	drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
 
-	if (fb_helper->delayed_hotplug) {
-		fb_helper->delayed_hotplug = false;
-		drm_fb_helper_hotplug_event(fb_helper);
-	}
 	return 0;
 }
 EXPORT_SYMBOL(drm_fb_helper_set_par);
@@ -995,19 +1000,21 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 	crtc_count = 0;
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		struct drm_display_mode *desired_mode;
+		int x, y;
 		desired_mode = fb_helper->crtc_info[i].desired_mode;
-
+		x = fb_helper->crtc_info[i].x;
+		y = fb_helper->crtc_info[i].y;
 		if (desired_mode) {
 			if (gamma_size == 0)
 				gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size;
-			if (desired_mode->hdisplay < sizes.fb_width)
-				sizes.fb_width = desired_mode->hdisplay;
-			if (desired_mode->vdisplay < sizes.fb_height)
-				sizes.fb_height = desired_mode->vdisplay;
-			if (desired_mode->hdisplay > sizes.surface_width)
-				sizes.surface_width = desired_mode->hdisplay;
-			if (desired_mode->vdisplay > sizes.surface_height)
-				sizes.surface_height = desired_mode->vdisplay;
+			if (desired_mode->hdisplay + x < sizes.fb_width)
+				sizes.fb_width = desired_mode->hdisplay + x;
+			if (desired_mode->vdisplay + y < sizes.fb_height)
+				sizes.fb_height = desired_mode->vdisplay + y;
+			if (desired_mode->hdisplay + x > sizes.surface_width)
+				sizes.surface_width = desired_mode->hdisplay + x;
+			if (desired_mode->vdisplay + y > sizes.surface_height)
+				sizes.surface_height = desired_mode->vdisplay + y;
 			crtc_count++;
 		}
 	}
@@ -1307,6 +1314,7 @@ static void drm_enable_connectors(struct drm_fb_helper *fb_helper,
 
 static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
 			      struct drm_display_mode **modes,
+			      struct drm_fb_offset *offsets,
 			      bool *enabled, int width, int height)
 {
 	int count, i, j;
@@ -1378,27 +1386,88 @@ static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
 	return false;
 }
 
+static int drm_get_tile_offsets(struct drm_fb_helper *fb_helper,
+				struct drm_display_mode **modes,
+				struct drm_fb_offset *offsets,
+				int idx,
+				int h_idx, int v_idx)
+{
+	struct drm_fb_helper_connector *fb_helper_conn;
+	int i;
+	int hoffset = 0, voffset = 0;
+
+	for (i = 0; i < fb_helper->connector_count; i++) {
+		fb_helper_conn = fb_helper->connector_info[i];
+		if (!fb_helper_conn->connector->has_tile)
+			continue;
+
+		if (!modes[i] && (h_idx || v_idx)) {
+			DRM_DEBUG_KMS("no modes for connector tiled %d %d\n", i,
+				      fb_helper_conn->connector->base.id);
+			continue;
+		}
+		if (fb_helper_conn->connector->tile_h_loc < h_idx)
+			hoffset += modes[i]->hdisplay;
+
+		if (fb_helper_conn->connector->tile_v_loc < v_idx)
+			voffset += modes[i]->vdisplay;
+	}
+	offsets[idx].x = hoffset;
+	offsets[idx].y = voffset;
+	DRM_DEBUG_KMS("returned %d %d for %d %d\n", hoffset, voffset, h_idx, v_idx);
+	return 0;
+}
+
 static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
 				 struct drm_display_mode **modes,
+				 struct drm_fb_offset *offsets,
 				 bool *enabled, int width, int height)
 {
 	struct drm_fb_helper_connector *fb_helper_conn;
 	int i;
-
+	uint64_t conn_configured = 0, mask;
+	int tile_pass = 0;
+	mask = (1 << fb_helper->connector_count) - 1;
+retry:
 	for (i = 0; i < fb_helper->connector_count; i++) {
 		fb_helper_conn = fb_helper->connector_info[i];
 
-		if (enabled[i] == false)
+		if (conn_configured & (1 << i))
 			continue;
 
+		if (enabled[i] == false) {
+			conn_configured |= (1 << i);
+			continue;
+		}
+
+		/* first pass over all the untiled connectors */
+		if (tile_pass == 0 && fb_helper_conn->connector->has_tile)
+			continue;
+
+		if (tile_pass == 1) {
+			if (fb_helper_conn->connector->tile_h_loc != 0 ||
+			    fb_helper_conn->connector->tile_v_loc != 0)
+				continue;
+
+		} else {
+			if (fb_helper_conn->connector->tile_h_loc != tile_pass -1 &&
+			    fb_helper_conn->connector->tile_v_loc != tile_pass - 1)
+			/* if this tile_pass doesn't cover any of the tiles - keep going */
+				continue;
+
+			/* find the tile offsets for this pass - need
+			   to find all tiles left and above */
+			drm_get_tile_offsets(fb_helper, modes, offsets,
+					     i, fb_helper_conn->connector->tile_h_loc, fb_helper_conn->connector->tile_v_loc);
+		}
 		DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
 			      fb_helper_conn->connector->base.id);
 
 		/* got for command line mode first */
 		modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
 		if (!modes[i]) {
-			DRM_DEBUG_KMS("looking for preferred mode on connector %d\n",
-				      fb_helper_conn->connector->base.id);
+			DRM_DEBUG_KMS("looking for preferred mode on connector %d %d\n",
+				      fb_helper_conn->connector->base.id, fb_helper_conn->connector->tile_group ? fb_helper_conn->connector->tile_group->id : 0);
 			modes[i] = drm_has_preferred_mode(fb_helper_conn, width, height);
 		}
 		/* No preferred modes, pick one off the list */
@@ -1408,6 +1477,12 @@ static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
 		}
 		DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
 			  "none");
+		conn_configured |= (1 << i);
+	}
+
+	if ((conn_configured & mask) != mask) {
+		tile_pass++;
+		goto retry;
 	}
 	return true;
 }
@@ -1497,6 +1572,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 	struct drm_device *dev = fb_helper->dev;
 	struct drm_fb_helper_crtc **crtcs;
 	struct drm_display_mode **modes;
+	struct drm_fb_offset *offsets;
 	struct drm_mode_set *modeset;
 	bool *enabled;
 	int width, height;
@@ -1511,9 +1587,11 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 			sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
 	modes = kcalloc(dev->mode_config.num_connector,
 			sizeof(struct drm_display_mode *), GFP_KERNEL);
+	offsets = kcalloc(dev->mode_config.num_connector,
+			  sizeof(struct drm_fb_offset), GFP_KERNEL);
 	enabled = kcalloc(dev->mode_config.num_connector,
 			  sizeof(bool), GFP_KERNEL);
-	if (!crtcs || !modes || !enabled) {
+	if (!crtcs || !modes || !enabled || !offsets) {
 		DRM_ERROR("Memory allocation failed\n");
 		goto out;
 	}
@@ -1523,14 +1601,16 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 
 	if (!(fb_helper->funcs->initial_config &&
 	      fb_helper->funcs->initial_config(fb_helper, crtcs, modes,
+					       offsets,
 					       enabled, width, height))) {
 		memset(modes, 0, dev->mode_config.num_connector*sizeof(modes[0]));
 		memset(crtcs, 0, dev->mode_config.num_connector*sizeof(crtcs[0]));
+		memset(offsets, 0, dev->mode_config.num_connector*sizeof(offsets[0]));
 
-		if (!drm_target_cloned(fb_helper,
-				       modes, enabled, width, height) &&
-		    !drm_target_preferred(fb_helper,
-					  modes, enabled, width, height))
+		if (!drm_target_cloned(fb_helper, modes, offsets,
+				       enabled, width, height) &&
+		    !drm_target_preferred(fb_helper, modes, offsets,
+					  enabled, width, height))
 			DRM_ERROR("Unable to find initial modes\n");
 
 		DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n",
@@ -1550,18 +1630,23 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 	for (i = 0; i < fb_helper->connector_count; i++) {
 		struct drm_display_mode *mode = modes[i];
 		struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
+		struct drm_fb_offset *offset = &offsets[i];
 		modeset = &fb_crtc->mode_set;
 
 		if (mode && fb_crtc) {
-			DRM_DEBUG_KMS("desired mode %s set on crtc %d\n",
-				      mode->name, fb_crtc->mode_set.crtc->base.id);
+			DRM_DEBUG_KMS("desired mode %s set on crtc %d (%d,%d)\n",
+				      mode->name, fb_crtc->mode_set.crtc->base.id, offset->x, offset->y);
 			fb_crtc->desired_mode = mode;
+			fb_crtc->x = offset->x;
+			fb_crtc->y = offset->y;
 			if (modeset->mode)
 				drm_mode_destroy(dev, modeset->mode);
 			modeset->mode = drm_mode_duplicate(dev,
 							   fb_crtc->desired_mode);
 			modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;
 			modeset->fb = fb_helper->fb;
+			modeset->x = offset->x;
+			modeset->y = offset->y;
 		}
 	}
 
@@ -1578,6 +1663,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 out:
 	kfree(crtcs);
 	kfree(modes);
+	kfree(offsets);
 	kfree(enabled);
 }
 

drivers/gpu/drm/i915/intel_dp_mst.c

@@ -283,7 +283,7 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct intel_dp *intel_dp = intel_connector->mst_port;
 
-	return drm_dp_mst_detect_port(&intel_dp->mst_mgr, intel_connector->port);
+	return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr, intel_connector->port);
 }
 
 static int
@@ -414,6 +414,8 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
 	intel_dp_add_properties(intel_dp, connector);
 
 	drm_object_attach_property(&connector->base, dev->mode_config.path_property, 0);
+	drm_object_attach_property(&connector->base, dev->mode_config.tile_property, 0);
+
 	drm_mode_connector_set_path_property(connector, pathprop);
 	drm_reinit_primary_mode_group(dev);
 	mutex_lock(&dev->mode_config.mutex);

drivers/gpu/drm/i915/intel_fbdev.c

@@ -324,6 +324,7 @@ intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
 static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 				    struct drm_fb_helper_crtc **crtcs,
 				    struct drm_display_mode **modes,
+				    struct drm_fb_offset *offsets,
 				    bool *enabled, int width, int height)
 {
 	struct drm_device *dev = fb_helper->dev;
@@ -332,6 +333,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 	bool fallback = true;
 	int num_connectors_enabled = 0;
 	int num_connectors_detected = 0;
+	uint64_t conn_configured = 0, mask;
+	int pass = 0;
 
 	save_enabled = kcalloc(dev->mode_config.num_connector, sizeof(bool),
 			       GFP_KERNEL);
@@ -339,7 +342,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		return false;
 
 	memcpy(save_enabled, enabled, dev->mode_config.num_connector);
-
+	mask = (1 << fb_helper->connector_count) - 1;
+retry:
 	for (i = 0; i < fb_helper->connector_count; i++) {
 		struct drm_fb_helper_connector *fb_conn;
 		struct drm_connector *connector;
@@ -349,12 +353,19 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		fb_conn = fb_helper->connector_info[i];
 		connector = fb_conn->connector;
 
+		if (conn_configured & (1 << i))
+			continue;
+
+		if (pass == 0 && !connector->has_tile)
+			continue;
+
 		if (connector->status == connector_status_connected)
 			num_connectors_detected++;
 
 		if (!enabled[i]) {
 			DRM_DEBUG_KMS("connector %s not enabled, skipping\n",
 				      connector->name);
+			conn_configured |= (1 << i);
 			continue;
 		}
 
@@ -373,6 +384,7 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 			DRM_DEBUG_KMS("connector %s has no encoder or crtc, skipping\n",
 				      connector->name);
 			enabled[i] = false;
+			conn_configured |= (1 << i);
 			continue;
 		}
 
@@ -400,8 +412,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 
 		/* try for preferred next */
 		if (!modes[i]) {
-			DRM_DEBUG_KMS("looking for preferred mode on connector %s\n",
-				      connector->name);
+			DRM_DEBUG_KMS("looking for preferred mode on connector %s %d\n",
+				      connector->name, connector->has_tile);
 			modes[i] = drm_has_preferred_mode(fb_conn, width,
 							  height);
 		}
@@ -444,6 +456,12 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 			      modes[i]->flags & DRM_MODE_FLAG_INTERLACE ? "i" :"");
 
 		fallback = false;
+		conn_configured |= (1 << i);
+	}
+
+	if ((conn_configured & mask) != mask) {
+		pass++;
+		goto retry;
 	}
 
 	/*

include/drm/drm_crtc.h

@@ -137,6 +137,14 @@ struct drm_display_info {
 	u8 cea_rev;
 };
 
+/* data corresponds to displayid vend/prod/serial */
+struct drm_tile_group {
+	struct kref refcount;
+	struct drm_device *dev;
+	int id;
+	u8 group_data[8];
+};
+
 struct drm_framebuffer_funcs {
 	/* note: use drm_framebuffer_remove() */
 	void (*destroy)(struct drm_framebuffer *framebuffer);
@@ -599,6 +607,15 @@ struct drm_encoder {
  * @bad_edid_counter: track sinks that give us an EDID with invalid checksum
  * @debugfs_entry: debugfs directory for this connector
  * @state: current atomic state for this connector
+ * @has_tile: is this connector connected to a tiled monitor
+ * @tile_group: tile group for the connected monitor
+ * @tile_is_single_monitor: whether the tile is one monitor housing
+ * @num_h_tile: number of horizontal tiles in the tile group
+ * @num_v_tile: number of vertical tiles in the tile group
+ * @tile_h_loc: horizontal location of this tile
+ * @tile_v_loc: vertical location of this tile
+ * @tile_h_size: horizontal size of this tile.
+ * @tile_v_size: vertical size of this tile.
  *
  * Each connector may be connected to one or more CRTCs, or may be clonable by
  * another connector if they can share a CRTC.  Each connector also has a specific
@@ -634,6 +651,8 @@ struct drm_connector {
 
 	struct drm_property_blob *path_blob_ptr;
 
+	struct drm_property_blob *tile_blob_ptr;
+
 	uint8_t polled; /* DRM_CONNECTOR_POLL_* */
 
 	/* requested DPMS state */
@@ -661,6 +680,15 @@ struct drm_connector {
 	struct dentry *debugfs_entry;
 
 	struct drm_connector_state *state;
+
+	/* DisplayID bits */
+	bool has_tile;
+	struct drm_tile_group *tile_group;
+	bool tile_is_single_monitor;
+
+	uint8_t num_h_tile, num_v_tile;
+	uint8_t tile_h_loc, tile_v_loc;
+	uint16_t tile_h_size, tile_v_size;
 };
 
 /**
@@ -978,6 +1006,7 @@ struct drm_mode_config {
 	struct drm_modeset_acquire_ctx *acquire_ctx; /* for legacy _lock_all() / _unlock_all() */
 	struct mutex idr_mutex; /* for IDR management */
 	struct idr crtc_idr; /* use this idr for all IDs, fb, crtc, connector, modes - just makes life easier */
+	struct idr tile_idr; /* use this idr for all IDs, fb, crtc, connector, modes - just makes life easier */
 	/* this is limited to one for now */
 
 	struct mutex fb_lock; /* proctects global and per-file fb lists */
@@ -1021,6 +1050,7 @@ struct drm_mode_config {
 	struct drm_property *edid_property;
 	struct drm_property *dpms_property;
 	struct drm_property *path_property;
+	struct drm_property *tile_property;
 	struct drm_property *plane_type_property;
 	struct drm_property *rotation_property;
 
@@ -1190,6 +1220,7 @@ extern void drm_mode_config_cleanup(struct drm_device *dev);
 
 extern int drm_mode_connector_set_path_property(struct drm_connector *connector,
 						const char *path);
+int drm_mode_connector_set_tile_property(struct drm_connector *connector);
 extern int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 						   const struct edid *edid);
 
@@ -1326,6 +1357,13 @@ extern void drm_set_preferred_mode(struct drm_connector *connector,
 extern int drm_edid_header_is_valid(const u8 *raw_edid);
 extern bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid);
 extern bool drm_edid_is_valid(struct edid *edid);
+
+extern struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
+							 char topology[8]);
+extern struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
+					       char topology[8]);
+extern void drm_mode_put_tile_group(struct drm_device *dev,
+				   struct drm_tile_group *tg);
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
 					   int hsize, int vsize, int fresh,
 					   bool rb);

include/drm/drm_displayid.h

+/*
+ * Copyright © 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef DRM_DISPLAYID_H
+#define DRM_DISPLAYID_H
+
+#define DATA_BLOCK_PRODUCT_ID 0x00
+#define DATA_BLOCK_DISPLAY_PARAMETERS 0x01
+#define DATA_BLOCK_COLOR_CHARACTERISTICS 0x02
+#define DATA_BLOCK_TYPE_1_DETAILED_TIMING 0x03
+#define DATA_BLOCK_TYPE_2_DETAILED_TIMING 0x04
+#define DATA_BLOCK_TYPE_3_SHORT_TIMING 0x05
+#define DATA_BLOCK_TYPE_4_DMT_TIMING 0x06
+#define DATA_BLOCK_VESA_TIMING 0x07
+#define DATA_BLOCK_CEA_TIMING 0x08
+#define DATA_BLOCK_VIDEO_TIMING_RANGE 0x09
+#define DATA_BLOCK_PRODUCT_SERIAL_NUMBER 0x0a
+#define DATA_BLOCK_GP_ASCII_STRING 0x0b
+#define DATA_BLOCK_DISPLAY_DEVICE_DATA 0x0c
+#define DATA_BLOCK_INTERFACE_POWER_SEQUENCING 0x0d
+#define DATA_BLOCK_TRANSFER_CHARACTERISTICS 0x0e
+#define DATA_BLOCK_DISPLAY_INTERFACE 0x0f
+#define DATA_BLOCK_STEREO_DISPLAY_INTERFACE 0x10
+#define DATA_BLOCK_TILED_DISPLAY 0x12
+
+#define DATA_BLOCK_VENDOR_SPECIFIC 0x7f
+
+#define PRODUCT_TYPE_EXTENSION 0
+#define PRODUCT_TYPE_TEST 1
+#define PRODUCT_TYPE_PANEL 2
+#define PRODUCT_TYPE_MONITOR 3
+#define PRODUCT_TYPE_TV 4
+#define PRODUCT_TYPE_REPEATER 5
+#define PRODUCT_TYPE_DIRECT_DRIVE 6
+
+struct displayid_hdr {
+	u8 rev;
+	u8 bytes;
+	u8 prod_id;
+	u8 ext_count;
+} __packed;
+
+struct displayid_block {
+	u8 tag;
+	u8 rev;
+	u8 num_bytes;
+} __packed;
+
+struct displayid_tiled_block {
+	struct displayid_block base;
+	u8 tile_cap;
+	u8 topo[3];
+	u8 tile_size[4];
+	u8 tile_pixel_bezel[5];
+	u8 topology_id[8];
+} __packed;
+
+#endif

include/drm/drm_dp_mst_helper.h

@@ -92,6 +92,8 @@ struct drm_dp_mst_port {
 	struct drm_dp_vcpi vcpi;
 	struct drm_connector *connector;
 	struct drm_dp_mst_topology_mgr *mgr;
+
+	struct edid *cached_edid; /* for DP logical ports - make tiling work */
 };
 
 /**
@@ -474,7 +476,7 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
 
 
-enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
 
 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
 

include/drm/drm_edid.h

@@ -27,12 +27,14 @@
 
 #define EDID_LENGTH 128
 #define DDC_ADDR 0x50
+#define DDC_ADDR2 0x52 /* E-DDC 1.2 - where DisplayID can hide */
 
 #define CEA_EXT	    0x02
 #define VTB_EXT	    0x10
 #define DI_EXT	    0x40
 #define LS_EXT	    0x50
 #define MI_EXT	    0x60
+#define DISPLAYID_EXT 0x70
 
 struct est_timings {
 	u8 t1;

include/drm/drm_fb_helper.h

@@ -34,9 +34,14 @@ struct drm_fb_helper;
 
 #include <linux/kgdb.h>
 
+struct drm_fb_offset {
+	int x, y;
+};
+
 struct drm_fb_helper_crtc {
 	struct drm_mode_set mode_set;
 	struct drm_display_mode *desired_mode;
+	int x, y;
 };
 
 struct drm_fb_helper_surface_size {
@@ -72,6 +77,7 @@ struct drm_fb_helper_funcs {
 	bool (*initial_config)(struct drm_fb_helper *fb_helper,
 			       struct drm_fb_helper_crtc **crtcs,
 			       struct drm_display_mode **modes,
+			       struct drm_fb_offset *offsets,
 			       bool *enabled, int width, int height);
 };