[PATCH 5/6] libweston: fbdev: Attempt to detect the first framebuffer device in the seat, instead of defaulting to /dev/fb0

[nerdopolis]

---
 libweston/compositor-fbdev.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
index a9cc08be..99362b8a 100644
--- a/libweston/compositor-fbdev.c
+++ b/libweston/compositor-fbdev.c
@@ -732,6 +732,12 @@ fbdev_backend_create(struct weston_compositor *compositor,
 	const char *seat_id = default_seat;
 	const char *session_seat;
 
+	struct udev_enumerate *e;
+	struct udev_list_entry *entry;
+	const char *path, *device_seat;
+        char *fb_device;
+	struct udev_device *device;
+
 	session_seat=getenv("XDG_SEAT");
 	if (session_seat)
 		seat_id=session_seat;
@@ -755,6 +761,33 @@ fbdev_backend_create(struct weston_compositor *compositor,
 		goto out_compositor;
 	}
 
+	e = udev_enumerate_new(backend->udev);
+	udev_enumerate_add_match_subsystem(e, "graphics");
+	udev_enumerate_add_match_sysname(e, "fb[0-9]*");
+
+	udev_enumerate_scan_devices(e);
+	fb_device = NULL;
+	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
+
+		path = udev_list_entry_get_name(entry);
+		device = udev_device_new_from_syspath(backend->udev, path);
+		if (!device)
+			continue;
+		device_seat = udev_device_get_property_value(device, "ID_SEAT");
+		if (!device_seat)
+			device_seat = default_seat;
+		if (!strcmp(device_seat, seat_id)) {
+			fb_device = udev_device_get_devnode(device);
+			if (fb_device && !param->device)
+				param->device = strdup(fb_device);
+			udev_device_unref(device);
+			udev_enumerate_unref(e);
+			break;
+		}
+	}
+	if (!param->device)
+		param->device=strdup("/dev/fb0");
+
 	/* Set up the TTY. */
 	backend->session_listener.notify = session_notify;
 	wl_signal_add(&compositor->session_signal,
@@ -802,8 +835,6 @@ out_compositor:
 static void
 config_init_to_defaults(struct weston_fbdev_backend_config *config)
 {
-	/* TODO: Ideally, available frame buffers should be enumerated using
-	 * udev, rather than passing a device node in as a parameter. */
 	config->tty = 0; /* default to current tty */
 	config->device = "/dev/fb0"; /* default frame buffer */
 	config->seat_id = "seat0"; /* default seat*/
-- 
2.14.1