new/yocto/meta-rockchip/recipes-graphics/wayland/weston_10.0.2/0013-backend-drm-Support-selecting-monitors.patch

From 475bf406ef30aa6c04efc35caf2ff748a4a20df9 Mon Sep 17 00:00:00 2001
From: Jeffy Chen <jeffy.chen@rock-chips.com>
Date: Tue, 23 Jun 2020 10:05:48 +0800
Subject: [PATCH 13/79] backend-drm: Support selecting monitors

Using these environments:

WESTON_DRM_PRIMARY:
  Specify primary connector.
WESTON_DRM_SINGLE_HEAD:
  Force using single connector.
WESTON_DRM_HEAD_FALLBACK:
  Fallback to any available connector if none matched.
WESTON_DRM_HEAD_FALLBACK_ALL:
  Fallback to all available connector if none matched.
WESTON_DRM_PREFER_EXTERNAL_DUAL:
  Prefer external connectors, and also enable internal ones.
WESTON_DRM_PREFER_EXTERNAL:
  Prefer external connectors, and disable internal ones if any matched.

WESTON_DRM_HEAD_MODE:
  default(match primary->internal->external)
  primary(match primary only)
  internal(match primary->internal)
  external(match primary->external)
  external-dual(match primary->external->internal)

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
 compositor/main.c                    |  26 +-
 desktop-shell/shell.c                |  24 +-
 include/libweston/libweston.h        |   2 +
 libweston/backend-drm/drm-internal.h |  23 ++
 libweston/backend-drm/drm.c          | 369 ++++++++++++++++++++++++---
 libweston/backend-drm/kms.c          |  42 ++-
 libweston/compositor.c               |  42 ++-
 7 files changed, 471 insertions(+), 57 deletions(-)

diff --git a/compositor/main.c b/compositor/main.c
index e946b4a..47bf540 100644
--- a/compositor/main.c
+++ b/compositor/main.c
@@ -2067,7 +2067,7 @@ drm_head_prepare_enable(struct wet_compositor *wet,
 	char *output_name = NULL;
 	char *mode = NULL;
 
-	section = drm_config_find_controlling_output_section(wet->config, name);
+	section = head->section;
 	if (section) {
 		/* skip outputs that are explicitly off, or non-desktop and not
 		 * explicitly enabled. The backend turns them off automatically.
@@ -2097,11 +2097,10 @@ static bool
 drm_head_should_force_enable(struct wet_compositor *wet,
 			     struct weston_head *head)
 {
-	const char *name = weston_head_get_name(head);
 	struct weston_config_section *section;
 	bool force;
 
-	section = drm_config_find_controlling_output_section(wet->config, name);
+	section = head->section;
 	if (!section)
 		return false;
 
@@ -2289,6 +2288,25 @@ drm_head_disable(struct weston_head *head)
 		wet_output_destroy(output);
 }
 
+static bool
+drm_head_update_output_section(struct weston_head *head)
+{
+	struct weston_compositor *compositor = head->compositor;
+	struct wet_compositor *wet = to_wet_compositor(compositor);
+	const char *name = weston_head_get_name(head);
+	struct weston_config_section *section;
+
+	if (head->section)
+		return true;
+
+	section = drm_config_find_controlling_output_section(wet->config, name);
+	if (!section)
+		return false;
+
+	head->section = section;
+	return true;
+}
+
 static void
 drm_heads_changed(struct wl_listener *listener, void *arg)
 {
@@ -2304,6 +2322,8 @@ drm_heads_changed(struct wl_listener *listener, void *arg)
 	 * output.
 	 */
 	while ((head = weston_compositor_iterate_heads(compositor, head))) {
+		drm_head_update_output_section(head);
+
 		connected = weston_head_is_connected(head);
 		enabled = weston_head_is_enabled(head);
 		changed = weston_head_is_device_changed(head);
diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index 15c148f..515c57f 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -3988,6 +3988,9 @@ shell_fade_done_for_output(struct weston_view_animation *animation, void *data)
 	struct shell_output *shell_output = data;
 	struct desktop_shell *shell = shell_output->shell;
 
+	if (!shell_output->fade.view)
+		return;
+
 	shell_output->fade.animation = NULL;
 	switch (shell_output->fade.type) {
 	case FADE_IN:
@@ -4021,6 +4024,7 @@ shell_fade_create_surface_for_output(struct desktop_shell *shell, struct shell_o
 
 	weston_surface_set_size(surface, shell_output->output->width, shell_output->output->height);
 	weston_view_set_position(view, shell_output->output->x, shell_output->output->y);
+	weston_view_set_output(view, shell_output->output);
 	weston_surface_set_color(surface, 0.0, 0.0, 0.0, 1.0);
 	weston_layer_entry_insert(&compositor->fade_layer.view_list,
 				  &view->layer_link);
@@ -4841,8 +4845,11 @@ shell_output_destroy(struct shell_output *shell_output)
 	}
 
 	if (shell_output->fade.view) {
+		struct weston_view *view = shell_output->fade.view;
+		shell_output->fade.view = NULL;
+
 		/* destroys the view as well */
-		weston_surface_destroy(shell_output->fade.view->surface);
+		weston_surface_destroy(view->surface);
 	}
 
 	if (shell_output->fade.startup_timer)
@@ -4946,12 +4953,25 @@ handle_output_move_layer(struct desktop_shell *shell,
 static void
 handle_output_move(struct wl_listener *listener, void *data)
 {
+	struct weston_output *output = data;
+	struct weston_compositor *compositor = output->compositor;
 	struct desktop_shell *shell;
 
 	shell = container_of(listener, struct desktop_shell,
 			     output_move_listener);
 
-	shell_for_each_layer(shell, handle_output_move_layer, data);
+	if (shell->lock_surface)
+		shell->lock_surface->committed(shell->lock_surface, 0, 0);
+
+	/* Only move normal layers for non-default output */
+	if (output != get_default_output(compositor)) {
+		shell_for_each_layer(shell, handle_output_move_layer, data);
+		return;
+	}
+
+	handle_output_move_layer(shell, &shell->lock_layer, data);
+	handle_output_move_layer(shell, &shell->background_layer, data);
+	handle_output_move_layer(shell, &shell->panel_layer, data);
 }
 
 static void
diff --git a/include/libweston/libweston.h b/include/libweston/libweston.h
index c6ba508..bdecc19 100644
--- a/include/libweston/libweston.h
+++ b/include/libweston/libweston.h
@@ -261,6 +261,8 @@ struct weston_head {
 
 	/** Current content protection status */
 	enum weston_hdcp_protection current_protection;
+
+	struct weston_config_section *section; /**< config section **/
 };
 
 /** Content producer for heads
diff --git a/libweston/backend-drm/drm-internal.h b/libweston/backend-drm/drm-internal.h
index 4860088..3f42a25 100644
--- a/libweston/backend-drm/drm-internal.h
+++ b/libweston/backend-drm/drm-internal.h
@@ -110,6 +110,10 @@
 
 #define MAX_CLONED_CONNECTORS 4
 
+/* Min duration between drm outputs update requests, to avoid glith */
+#define DRM_MIN_UPDATE_MS	1000
+
+#define DRM_RESIZE_FREEZE_MS    600
 
 /**
  * Represents the values of an enum-type KMS property
@@ -249,6 +253,10 @@ enum actions_needed_dmabuf_feedback {
 	ACTION_NEEDED_REMOVE_SCANOUT_TRANCHE = (1 << 1),
 };
 
+struct drm_head;
+struct drm_backend;
+typedef bool (*drm_head_match_t) (struct drm_backend *, struct drm_head *);
+
 struct drm_backend {
 	struct weston_backend base;
 	struct weston_compositor *compositor;
@@ -264,6 +272,7 @@ struct drm_backend {
 		int fd;
 		char *filename;
 		dev_t devnum;
+		char *syspath;
 	} drm;
 	struct gbm_device *gbm;
 	struct wl_listener session_listener;
@@ -311,6 +320,18 @@ struct drm_backend {
 	bool fb_modifiers;
 
 	struct weston_log_scope *debug;
+
+	struct wl_event_source *hotplug_timer;
+	bool pending_update;
+	int64_t last_update_ms;
+	int64_t last_resize_ms;
+
+	bool single_head;
+	bool head_fallback;
+	bool head_fallback_all;
+	drm_head_match_t *head_matches;
+	struct drm_head *primary_head;
+	struct wl_listener output_create_listener;
 };
 
 struct drm_mode {
@@ -574,6 +595,8 @@ struct drm_output {
 	bool virtual;
 
 	submit_frame_cb virtual_submit_frame;
+
+	bool state_invalid;
 };
 
 static inline struct drm_head *
diff --git a/libweston/backend-drm/drm.c b/libweston/backend-drm/drm.c
index d6a8588..4e00933 100644
--- a/libweston/backend-drm/drm.c
+++ b/libweston/backend-drm/drm.c
@@ -47,6 +47,7 @@
 
 #include <libudev.h>
 
+#include <libweston/config-parser.h>
 #include <libweston/libweston.h>
 #include <libweston/backend-drm.h>
 #include <libweston/weston-log.h>
@@ -68,6 +69,44 @@
 
 static const char default_seat[] = "seat0";
 
+static inline bool
+drm_head_is_external(struct drm_head *head)
+{
+	drmModeConnector *conn = head->connector.conn;
+	switch (conn->connector_type) {
+		case DRM_MODE_CONNECTOR_LVDS:
+		case DRM_MODE_CONNECTOR_eDP:
+#ifdef DRM_MODE_CONNECTOR_DSI
+		case DRM_MODE_CONNECTOR_DSI:
+#endif
+			return false;
+		default:
+			return true;
+	}
+};
+
+static void
+drm_backend_update_outputs(struct drm_backend *b)
+{
+	struct weston_output *primary;
+
+	if (!b->primary_head)
+		return;
+
+	primary = b->primary_head->base.output;
+	if (!primary)
+		return;
+
+	/* Move primary output to (0,0) */
+	wl_list_remove(&primary->link);
+	wl_list_insert(&b->compositor->output_list, &primary->link);
+
+	/* Reflow outputs */
+	weston_compositor_reflow_outputs(b->compositor);
+
+	weston_compositor_damage_all(b->compositor);
+}
+
 static void
 drm_backend_create_faked_zpos(struct drm_backend *b)
 {
@@ -460,10 +499,13 @@ drm_output_repaint(struct weston_output *output_base,
 		   pixman_region32_t *damage,
 		   void *repaint_data)
 {
+	struct drm_backend *b = to_drm_backend(output_base->compositor);
 	struct drm_pending_state *pending_state = repaint_data;
 	struct drm_output *output = to_drm_output(output_base);
 	struct drm_output_state *state = NULL;
 	struct drm_plane_state *scanout_state;
+	struct timespec now;
+	int64_t now_ms;
 
 	assert(!output->virtual);
 
@@ -472,6 +514,20 @@ drm_output_repaint(struct weston_output *output_base,
 
 	assert(!output->state_last);
 
+	weston_compositor_read_presentation_clock(b->compositor, &now);
+	now_ms = timespec_to_msec(&now);
+	if (now_ms < b->last_resize_ms + DRM_RESIZE_FREEZE_MS) {
+		/* Resize fullscreen/maxmium views(not always success) */
+		if (now_ms < b->last_resize_ms + DRM_RESIZE_FREEZE_MS)
+			wl_signal_emit(&b->compositor->output_resized_signal,
+				       output);
+
+		weston_output_damage(output_base);
+		weston_output_finish_frame(output_base, NULL,
+					   WP_PRESENTATION_FEEDBACK_INVALID);
+		return 0;
+	}
+
 	/* If planes have been disabled in the core, we might not have
 	 * hit assign_planes at all, so might not have valid output state
 	 * here. */
@@ -497,7 +553,7 @@ drm_output_repaint(struct weston_output *output_base,
 
 err:
 	drm_output_state_free(state);
-	return -1;
+	return 0;
 }
 
 /* Determine the type of vblank synchronization to use for the output.
@@ -718,6 +774,7 @@ drm_output_switch_mode(struct weston_output *output_base, struct weston_mode *mo
 	 *      content.
 	 */
 	b->state_invalid = true;
+	output->state_invalid = true;
 
 	if (b->use_pixman) {
 		drm_output_fini_pixman(output);
@@ -1271,6 +1328,7 @@ drm_output_attach_head(struct weston_output *output_base,
 		       struct weston_head *head_base)
 {
 	struct drm_backend *b = to_drm_backend(output_base->compositor);
+	struct drm_output *output = to_drm_output(output_base);
 
 	if (wl_list_length(&output_base->head_list) >= MAX_CLONED_CONNECTORS)
 		return -1;
@@ -1288,6 +1346,7 @@ drm_output_attach_head(struct weston_output *output_base,
 	 * will not clear the flag before this output is updated?
 	 */
 	b->state_invalid = true;
+	output->state_invalid = true;
 
 	weston_output_schedule_repaint(output_base);
 
@@ -1299,6 +1358,7 @@ drm_output_detach_head(struct weston_output *output_base,
 		       struct weston_head *head_base)
 {
 	struct drm_backend *b = to_drm_backend(output_base->compositor);
+	struct drm_output *output = to_drm_output(output_base);
 
 	if (!output_base->enabled)
 		return;
@@ -1307,6 +1367,7 @@ drm_output_detach_head(struct weston_output *output_base,
 	 * be driven. */
 	/* XXX: Ideally we'd do this per-output, not globally. */
 	b->state_invalid = true;
+	output->state_invalid = true;
 
 	weston_output_schedule_repaint(output_base);
 }
@@ -1795,6 +1856,7 @@ drm_output_detach_crtc(struct drm_output *output)
 
 	/* Force resetting unused CRTCs */
 	b->state_invalid = true;
+	output->state_invalid = true;
 }
 
 static int
@@ -1839,6 +1901,8 @@ drm_output_enable(struct weston_output *base)
 	output->base.switch_mode = drm_output_switch_mode;
 	output->base.set_gamma = drm_output_set_gamma;
 
+	output->state_invalid = true;
+
 	weston_log("Output %s (crtc %d) video modes:\n",
 		   output->base.name, output->crtc->crtc_id);
 	drm_output_print_modes(output);
@@ -2173,8 +2237,7 @@ drm_head_create(struct drm_backend *backend, drmModeConnector *conn,
 
 	head->backlight = backlight_init(drm_device, conn->connector_type);
 
-	if (conn->connector_type == DRM_MODE_CONNECTOR_LVDS ||
-	    conn->connector_type == DRM_MODE_CONNECTOR_eDP)
+	if (!drm_head_is_external(head))
 		weston_head_set_internal(&head->base);
 
 	if (drm_head_read_current_setup(head, backend) < 0) {
@@ -2335,71 +2398,77 @@ drm_backend_add_connector(struct drm_backend *b, drmModeConnector *conn,
 	return ret;
 }
 
-/** Find all connectors of the fd and create drm_head or drm_writeback objects
- * (depending on the type of connector they are) for each of them
- *
- * These objects are added to the DRM-backend lists of heads and writebacks.
- *
- * @param b The DRM-backend structure
- * @param drm_device udev device pointer
- * @param resources The DRM resources, it is taken with drmModeGetResources
- * @return 0 on success, -1 on failure
- */
-static int
-drm_backend_discover_connectors(struct drm_backend *b, struct udev_device *drm_device,
-				drmModeRes *resources)
+static bool
+resources_has_connector(drmModeRes *resources, uint32_t connector_id)
 {
-	drmModeConnector *conn;
-	int i, ret;
+	for (int i = 0; i < resources->count_connectors; i++) {
+		if (resources->connectors[i] == connector_id)
+			return true;
+	}
 
-	b->min_width  = resources->min_width;
-	b->max_width  = resources->max_width;
-	b->min_height = resources->min_height;
-	b->max_height = resources->max_height;
+	return false;
+}
 
-	for (i = 0; i < resources->count_connectors; i++) {
-		uint32_t connector_id = resources->connectors[i];
+/* based on compositor/main.c#drm_head_prepare_enable() */
+static bool
+drm_head_is_available(struct weston_head *head)
+{
+	struct weston_config_section *section;
+	char *mode = NULL;
 
-		conn = drmModeGetConnector(b->drm.fd, connector_id);
-		if (!conn)
-			continue;
+	section = head->section;
+	if (!section)
+		return true;
 
-		ret = drm_backend_add_connector(b, conn, drm_device);
-		if (ret < 0)
-			drmModeFreeConnector(conn);
+	/* skip outputs that are explicitly off, or non-desktop and not
+	 * explicitly enabled.
+	 */
+	weston_config_section_get_string(section, "mode", &mode, NULL);
+	if (mode && strcmp(mode, "off") == 0) {
+		free(mode);
+		return false;
 	}
 
-	return 0;
+	if (!mode && weston_head_is_non_desktop(head))
+		return false;
+
+	free(mode);
+	return true;
 }
 
 static bool
-resources_has_connector(drmModeRes *resources, uint32_t connector_id)
+drm_head_match_fallback(struct drm_backend *b, struct drm_head *head)
 {
-	for (int i = 0; i < resources->count_connectors; i++) {
-		if (resources->connectors[i] == connector_id)
-			return true;
-	}
+	if (b->head_fallback_all)
+		return true;
 
-	return false;
+	return b->head_fallback && !b->primary_head;
 }
 
-static void
+static int
 drm_backend_update_connectors(struct drm_backend *b, struct udev_device *drm_device)
 {
 	drmModeRes *resources;
 	drmModeConnector *conn;
 	struct weston_head *base, *base_next;
-	struct drm_head *head;
+	struct drm_head *head, *old_primary_head;
 	struct drm_writeback *writeback, *writeback_next;
+	drm_head_match_t *match = b->head_matches;
+	struct timespec now;
 	uint32_t connector_id;
 	int i, ret;
 
 	resources = drmModeGetResources(b->drm.fd);
 	if (!resources) {
 		weston_log("drmModeGetResources failed\n");
-		return;
+		return -1;
 	}
 
+	b->min_width  = resources->min_width;
+	b->max_width  = resources->max_width;
+	b->min_height = resources->min_height;
+	b->max_height = resources->max_height;
+
 	/* collect new connectors that have appeared, e.g. MST */
 	for (i = 0; i < resources->count_connectors; i++) {
 		connector_id = resources->connectors[i];
@@ -2456,6 +2525,65 @@ drm_backend_update_connectors(struct drm_backend *b, struct udev_device *drm_dev
 	}
 
 	drmModeFreeResources(resources);
+
+	old_primary_head = b->primary_head;
+	b->primary_head = NULL;
+
+	wl_list_for_each_safe(base, base_next,
+			      &b->compositor->head_list, compositor_link)
+		weston_head_set_connection_status(base, false);
+
+	/* Re-connect matched heads and find primary head */
+	while (*match) {
+		wl_list_for_each_safe(base, base_next,
+				      &b->compositor->head_list,
+				      compositor_link) {
+			drmModeConnector *conn;
+
+			if (!drm_head_is_available(base))
+				continue;
+
+			head = to_drm_head(base);
+			conn = head->connector.conn;
+
+			if (conn->connection != DRM_MODE_CONNECTED ||
+			    !(*match)(b, head))
+				continue;
+
+			weston_head_set_connection_status(base, true);
+
+			if (!b->primary_head) {
+				b->primary_head = head;
+
+				/* Done the single-head match */
+				if (b->single_head)
+					goto match_done;
+			}
+		}
+
+		/* Done the fallback match */
+		if (*match == drm_head_match_fallback)
+			goto match_done;
+
+		match++;
+
+		/* Try the fallback match */
+		if (!match && !b->primary_head)
+			*match = drm_head_match_fallback;
+	}
+match_done:
+
+	drm_backend_update_outputs(b);
+
+	weston_compositor_read_presentation_clock(b->compositor, &now);
+	b->last_update_ms = timespec_to_msec(&now);
+
+	/* Assume primary output's size changed */
+	if (b->primary_head && old_primary_head &&
+	    b->primary_head != old_primary_head)
+		b->last_resize_ms = b->last_update_ms;
+
+	return 0;
 }
 
 static enum wdrm_connector_property
@@ -2546,6 +2674,48 @@ udev_event_is_conn_prop_change(struct drm_backend *b,
 	return 1;
 }
 
+static void
+udev_hotplug_event(struct drm_backend *b, struct udev_device *device)
+{
+	struct timespec now;
+	int64_t now_ms, next_ms;
+
+	weston_compositor_read_presentation_clock(b->compositor, &now);
+	now_ms = timespec_to_msec(&now);
+
+	/* Already have a pending request */
+	if (b->pending_update)
+		return;
+
+	next_ms = b->last_update_ms + DRM_MIN_UPDATE_MS;
+	if (next_ms <= now_ms) {
+		/* Long enough to trigger a new request */
+		drm_backend_update_connectors(b, device);
+	} else {
+		/* Too close to the last request, schedule a new one */
+		b->pending_update = true;
+		wl_event_source_timer_update(b->hotplug_timer,
+					     next_ms - now_ms);
+	}
+}
+
+static int
+hotplug_timer_handler(void *data)
+{
+	struct drm_backend *b = data;
+	struct udev_device *device;
+	struct udev *udev;
+
+	udev = udev_monitor_get_udev(b->udev_monitor);
+	device = udev_device_new_from_syspath(udev, b->drm.syspath);
+
+	drm_backend_update_connectors(b, device);
+	b->pending_update = false;
+
+	udev_device_unref(device);
+	return 0;
+}
+
 static int
 udev_drm_event(int fd, uint32_t mask, void *data)
 {
@@ -2559,7 +2729,7 @@ udev_drm_event(int fd, uint32_t mask, void *data)
 		if (udev_event_is_conn_prop_change(b, event, &conn_id, &prop_id))
 			drm_backend_update_conn_props(b, conn_id, prop_id);
 		else
-			drm_backend_update_connectors(b, event);
+			udev_hotplug_event(b, event);
 	}
 
 	udev_device_unref(event);
@@ -2577,6 +2747,7 @@ drm_destroy(struct weston_compositor *ec)
 
 	udev_input_destroy(&b->input);
 
+	wl_event_source_remove(b->hotplug_timer);
 	wl_event_source_remove(b->udev_drm_source);
 	wl_event_source_remove(b->drm_source);
 
@@ -2627,6 +2798,10 @@ session_notify(struct wl_listener *listener, void *data)
 		weston_compositor_wake(compositor);
 		weston_compositor_damage_all(compositor);
 		b->state_invalid = true;
+
+		wl_list_for_each(output, &compositor->output_list, base.link)
+			output->state_invalid = true;
+
 		udev_input_enable(&b->input);
 	} else {
 		weston_log("deactivating session\n");
@@ -2987,6 +3162,14 @@ recorder_binding(struct weston_keyboard *keyboard, const struct timespec *time,
 }
 #endif
 
+static void
+output_create_notify(struct wl_listener *listener, void *data)
+{
+	struct drm_backend *b = container_of(listener, struct drm_backend,
+					     output_create_listener);
+
+	drm_backend_update_outputs(b);
+}
 
 static const struct weston_drm_output_api api = {
 	drm_output_set_mode,
@@ -2994,6 +3177,63 @@ static const struct weston_drm_output_api api = {
 	drm_output_set_seat,
 };
 
+enum drm_head_mode {
+	DRM_HEAD_MODE_DEFAULT,
+	DRM_HEAD_MODE_PRIMARY,
+	DRM_HEAD_MODE_INTERNAL,
+	DRM_HEAD_MODE_EXTERNAL,
+	DRM_HEAD_MODE_EXTERNAL_DUAL,
+};
+
+static bool
+drm_head_match_primary(struct drm_backend *b, struct drm_head *head)
+{
+	const char *buf = getenv("WESTON_DRM_PRIMARY");
+	return buf && !strcmp(buf, head->base.name);
+}
+
+static bool
+drm_head_match_external(struct drm_backend *b, struct drm_head *head)
+{
+	return drm_head_is_external(head);
+}
+
+static bool
+drm_head_match_internal(struct drm_backend *b, struct drm_head *head)
+{
+	return !drm_head_is_external(head);
+}
+
+#define DRM_HEAD_MAX_MATCHES 5
+static drm_head_match_t drm_head_matches[][DRM_HEAD_MAX_MATCHES] = {
+	[DRM_HEAD_MODE_DEFAULT] = {
+		drm_head_match_primary,
+		drm_head_match_internal,
+		drm_head_match_external,
+		NULL,
+	},
+	[DRM_HEAD_MODE_PRIMARY] = {
+		drm_head_match_primary,
+		NULL,
+	},
+	[DRM_HEAD_MODE_INTERNAL] = {
+		drm_head_match_primary,
+		drm_head_match_internal,
+		NULL,
+	},
+	[DRM_HEAD_MODE_EXTERNAL] = {
+		drm_head_match_primary,
+		drm_head_match_external,
+		NULL,
+	},
+	[DRM_HEAD_MODE_EXTERNAL_DUAL] = {
+		drm_head_match_primary,
+		drm_head_match_external,
+		drm_head_match_internal,
+		NULL,
+	},
+};
+
 static struct drm_backend *
 drm_backend_create(struct weston_compositor *compositor,
 		   struct weston_drm_backend_config *config)
@@ -3004,7 +3244,9 @@ drm_backend_create(struct weston_compositor *compositor,
 	const char *seat_id = default_seat;
 	const char *session_seat;
 	struct weston_drm_format_array *scanout_formats;
+	enum drm_head_mode head_mode = DRM_HEAD_MODE_DEFAULT;
 	drmModeRes *res;
+	char *buf;
 	int ret;
 
 	session_seat = getenv("XDG_SEAT");
@@ -3020,6 +3262,42 @@ drm_backend_create(struct weston_compositor *compositor,
 	if (b == NULL)
 		return NULL;
 
+	buf = getenv("WESTON_DRM_SINGLE_HEAD");
+	if (buf && buf[0] == '1')
+		b->single_head = true;
+
+	buf = getenv("WESTON_DRM_HEAD_FALLBACK");
+	if (buf && buf[0] == '1')
+		b->head_fallback = true;
+
+	buf = getenv("WESTON_DRM_HEAD_FALLBACK_ALL");
+	if (buf && buf[0] == '1')
+		b->head_fallback_all = true;
+
+	buf = getenv("WESTON_DRM_PREFER_EXTERNAL");
+	if (buf && buf[0] == '1') {
+		head_mode = DRM_HEAD_MODE_EXTERNAL;
+		b->head_fallback = true;
+	}
+
+	buf = getenv("WESTON_DRM_PREFER_EXTERNAL_DUAL");
+	if (buf && buf[0] == '1')
+		head_mode = DRM_HEAD_MODE_EXTERNAL_DUAL;
+
+	buf = getenv("WESTON_DRM_HEAD_MODE");
+	if (buf) {
+		if (!strcmp(buf, "primary"))
+			head_mode = DRM_HEAD_MODE_PRIMARY;
+		else if (!strcmp(buf, "internal"))
+			head_mode = DRM_HEAD_MODE_INTERNAL;
+		else if (!strcmp(buf, "external"))
+			head_mode = DRM_HEAD_MODE_EXTERNAL;
+		else if (!strcmp(buf, "external-dual"))
+			head_mode = DRM_HEAD_MODE_EXTERNAL_DUAL;
+	}
+
+	b->head_matches = drm_head_matches[head_mode];
+
 	b->state_invalid = true;
 	b->drm.fd = -1;
 
@@ -3115,7 +3393,7 @@ drm_backend_create(struct weston_compositor *compositor,
 	}
 
 	wl_list_init(&b->writeback_connector_list);
-	if (drm_backend_discover_connectors(b, drm_device, res) < 0) {
+	if (drm_backend_update_connectors(b, drm_device) < 0) {
 		weston_log("Failed to create heads for %s\n", b->drm.filename);
 		goto err_udev_input;
 	}
@@ -3154,6 +3432,10 @@ drm_backend_create(struct weston_compositor *compositor,
 
 	udev_device_unref(drm_device);
 
+	b->output_create_listener.notify = output_create_notify;
+	wl_signal_add(&b->compositor->output_created_signal,
+		      &b->output_create_listener);
+
 	weston_compositor_add_debug_binding(compositor, KEY_O,
 					    planes_binding, b);
 	weston_compositor_add_debug_binding(compositor, KEY_C,
@@ -3215,6 +3497,9 @@ drm_backend_create(struct weston_compositor *compositor,
 		goto err_udev_monitor;
 	}
 
+	b->hotplug_timer =
+		wl_event_loop_add_timer(loop, hotplug_timer_handler, b);
+
 	return b;
 
 err_udev_monitor:
diff --git a/libweston/backend-drm/kms.c b/libweston/backend-drm/kms.c
index 35113d5..4426af4 100644
--- a/libweston/backend-drm/kms.c
+++ b/libweston/backend-drm/kms.c
@@ -704,6 +704,8 @@ drm_output_apply_state_legacy(struct drm_output_state *state)
 
 	scanout_state =
 		drm_output_state_get_existing_plane(state, scanout_plane);
+	if (!scanout_state || !scanout_state->fb)
+		return 0;
 
 	/* The legacy SetCrtc API doesn't allow us to do scaling, and the
 	 * legacy PageFlip API doesn't allow us to do clipping either. */
@@ -721,7 +723,7 @@ drm_output_apply_state_legacy(struct drm_output_state *state)
 	assert(scanout_state->in_fence_fd == -1);
 
 	mode = to_drm_mode(output->base.current_mode);
-	if (backend->state_invalid ||
+	if (output->state_invalid ||
 	    !scanout_plane->state_cur->fb ||
 	    scanout_plane->state_cur->fb->strides[0] !=
 	    scanout_state->fb->strides[0]) {
@@ -735,6 +737,8 @@ drm_output_apply_state_legacy(struct drm_output_state *state)
 			weston_log("set mode failed: %s\n", strerror(errno));
 			goto err;
 		}
+
+		output->state_invalid = false;
 	}
 
 	pinfo = scanout_state->fb->format;
@@ -945,6 +949,11 @@ drm_output_apply_state_atomic(struct drm_output_state *state,
 		*flags |= DRM_MODE_ATOMIC_ALLOW_MODESET;
 	}
 
+	if (output->state_invalid) {
+		drm_debug(b, "\t\t\t[atomic] output state invalid, modeset OK\n");
+		*flags |= DRM_MODE_ATOMIC_ALLOW_MODESET;
+	}
+
 	if (state->dpms == WESTON_DPMS_ON) {
 		ret = drm_mode_ensure_blob(b, current_mode);
 		if (ret != 0)
@@ -1050,6 +1059,7 @@ drm_pending_state_apply_atomic(struct drm_pending_state *pending_state,
 	struct drm_output_state *output_state, *tmp;
 	struct drm_plane *plane;
 	drmModeAtomicReq *req = drmModeAtomicAlloc();
+	struct timespec now;
 	uint32_t flags;
 	int ret = 0;
 
@@ -1180,14 +1190,34 @@ drm_pending_state_apply_atomic(struct drm_pending_state *pending_state,
 		goto out;
 	}
 
+	weston_compositor_read_presentation_clock(b->compositor, &now);
+
 	wl_list_for_each_safe(output_state, tmp, &pending_state->output_list,
-			      link)
+			      link) {
+		struct drm_output *output = output_state->output;
+		struct drm_plane *scanout_plane = output->scanout_plane;
+		struct drm_plane_state *scanout_state =
+			drm_output_state_get_existing_plane(output_state,
+							    scanout_plane);
+
+		/* Don't have a new state to apply */
+		if (output_state->dpms == WESTON_DPMS_ON &&
+		    (!scanout_state || !scanout_state->fb))
+			continue;
+
 		drm_output_assign_state(output_state, mode);
+		output->state_invalid = false;
+
+		/* Not gonna receive flip event when dpms off */
+		if (output_state->dpms != WESTON_DPMS_ON)
+			drm_output_update_complete(output,
+						   WP_PRESENTATION_FEEDBACK_KIND_HW_COMPLETION,
+						   now.tv_sec,
+						   now.tv_nsec / 1000);
+	}
 
 	b->state_invalid = false;
 
-	assert(wl_list_empty(&pending_state->output_list));
-
 out:
 	drmModeAtomicFree(req);
 	drm_pending_state_free(pending_state);
@@ -1286,8 +1316,6 @@ drm_pending_state_apply(struct drm_pending_state *pending_state)
 
 	b->state_invalid = false;
 
-	assert(wl_list_empty(&pending_state->output_list));
-
 	drm_pending_state_free(pending_state);
 
 	return 0;
@@ -1339,8 +1367,6 @@ drm_pending_state_apply_sync(struct drm_pending_state *pending_state)
 
 	b->state_invalid = false;
 
-	assert(wl_list_empty(&pending_state->output_list));
-
 	drm_pending_state_free(pending_state);
 
 	return 0;
diff --git a/libweston/compositor.c b/libweston/compositor.c
index e184349..22a8593 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -157,6 +157,25 @@ weston_paint_node_destroy(struct weston_paint_node *pnode)
 	free(pnode);
 }
 
+static struct weston_layer *
+get_view_layer(struct weston_view *view);
+
+static bool
+weston_compositor_is_static_layer(struct weston_layer *layer)
+{
+	if (!layer)
+		return false;
+
+	switch (layer->position) {
+	case WESTON_LAYER_POSITION_BACKGROUND:
+	case WESTON_LAYER_POSITION_UI:
+	case WESTON_LAYER_POSITION_FADE:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /** Send wl_output events for mode and scale changes
  *
  * \param head Send on all resources bound to this head.
@@ -1367,6 +1386,22 @@ weston_view_assign_output(struct weston_view *ev)
 	uint32_t max, area, mask;
 	pixman_box32_t *e;
 
+	/* The static views should bind to the specific output */
+	if (weston_compositor_is_static_layer(get_view_layer(ev))) {
+		struct weston_view *view = ev;
+
+		while (view && !(output = view->output))
+			view = view->geometry.parent;
+
+		if (output && !output->destroying)
+			ev->output_mask |= 1u << output->id;
+		else
+			weston_view_set_output(ev, NULL);
+
+		weston_surface_assign_output(ev->surface);
+		return;
+	}
+
 	new_output = NULL;
 	max = 0;
 	mask = 0;
@@ -2942,12 +2977,14 @@ weston_output_repaint(struct weston_output *output, void *repaint_data)
 	if (output->dirty)
 		weston_output_update_matrix(output);
 
+	output->repaint_needed = false;
 	r = output->repaint(output, &output_damage, repaint_data);
 
 	pixman_region32_fini(&output_damage);
 
-	output->repaint_needed = false;
-	if (r == 0)
+	if (output->repaint_needed)
+		output->repaint_status = REPAINT_SCHEDULED;
+	else if (r == 0)
 		output->repaint_status = REPAINT_AWAITING_COMPLETION;
 
 	weston_compositor_repick(ec);
@@ -6407,6 +6444,7 @@ weston_compositor_remove_output(struct weston_output *output)
 	 * Use view_list in case the output did not go through repaint
 	 * after a view came on it, lacking a paint node. Just to be sure.
 	 */
+	weston_compositor_build_view_list(compositor, NULL);
 	wl_list_for_each(view, &compositor->view_list, link) {
 		if (view->output_mask & (1u << output->id))
 			weston_view_assign_output(view);
-- 
2.20.1