Refactor udev and drm initialization

backend/CMakeLists.txt

@@ -11,7 +11,7 @@ add_library(wlr-backend
     #wayland/wl_output.c
     drm/backend.c
     drm/drm.c
-    drm/udev.c
+    udev.c
     backend.c
     egl.c
 )

backend/backend.c

@@ -1,4 +1,5 @@
 #include <wayland-server.h>
+#include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -39,7 +40,27 @@ void wlr_backend_destroy(struct wlr_backend *backend) {
 struct wlr_backend *wlr_backend_autocreate(struct wl_display *display,
 		struct wlr_session *session) {
 	// TODO: Choose the most appropriate backend for the situation
+	// Attempt DRM+libinput
+	struct wlr_udev *udev;
+	if (!(udev = wlr_udev_create(display))) {
+		wlr_log(L_ERROR, "Failed to start udev");
+		goto error;
+	}
+	int gpu = wlr_udev_find_gpu(udev, session);
+	if (gpu == -1) {
+		wlr_log(L_ERROR, "Failed to open DRM device");
+		goto error_udev;
+	}
 	struct wlr_backend *wlr;
-	wlr = wlr_drm_backend_create(display, session);
+	wlr = wlr_drm_backend_create(display, session, udev, gpu);
+	if (!wlr) {
+		goto error_gpu;
+	}
 	return wlr;
+error_gpu:
+	close(gpu);
+error_udev:
+	wlr_udev_destroy(udev);
+error:
+	return NULL;
 }

backend/drm/backend.c

@@ -3,17 +3,16 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <assert.h>
 #include <wayland-server.h>
 #include <sys/stat.h>
-
 #include <wlr/session.h>
 #include <wlr/types.h>
 #include <wlr/common/list.h>
-
 #include "backend.h"
+#include "backend/udev.h"
 #include "backend/drm/backend.h"
 #include "backend/drm/drm.h"
-#include "backend/drm/udev.h"
 #include "common/log.h"
 
 static bool wlr_drm_backend_init(struct wlr_backend_state *state) {
@@ -30,7 +29,6 @@ static void wlr_drm_backend_destroy(struct wlr_backend_state *state) {
 		wlr_output_destroy(output->wlr_output);
 	}
 	wlr_drm_renderer_free(&state->renderer);
-	wlr_udev_free(&state->udev);
 	wlr_session_close_file(state->session, state->fd);
 	wlr_session_finish(state->session);
 	wl_event_source_remove(state->drm_event);
@@ -75,8 +73,14 @@ static void device_resumed(struct wl_listener *listener, void *data) {
 	}
 }
 
+static void drm_invalidated(struct wl_listener *listener, void *state) {
+	struct wlr_backend_state *drm = wl_container_of(listener, drm, drm_invalidated);
+	wlr_drm_scan_connectors(drm);
+}
+
 struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
-		struct wlr_session *session) {
+		struct wlr_session *session, struct wlr_udev *udev, int gpu_fd) {
+	assert(display && session && gpu_fd > 0);
 	struct wlr_backend_state *state = calloc(1, sizeof(struct wlr_backend_state));
 	if (!state) {
 		wlr_log(L_ERROR, "Allocation failed: %s", strerror(errno));
@@ -97,16 +101,10 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 		goto error_backend;
 	}
 
-	if (!wlr_udev_init(display, &state->udev)) {
-		wlr_log(L_ERROR, "Failed to start udev");
-		goto error_list;
-	}
-
-	state->fd = wlr_udev_find_gpu(&state->udev, state->session);
-	if (state->fd == -1) {
-		wlr_log(L_ERROR, "Failed to open DRM device");
-		goto error_udev;
-	}
+	state->fd = gpu_fd;
+	wl_list_init(&state->drm_invalidated.link);
+	state->drm_invalidated.notify = drm_invalidated;
+	wl_signal_add(&udev->invalidate_drm, &state->drm_invalidated);
 
 	struct stat st;
 	if (fstat(state->fd, &st) < 0) {
@@ -145,9 +143,6 @@ error_event:
 	wl_event_source_remove(state->drm_event);
 error_fd:
 	wlr_session_close_file(state->session, state->fd);
-error_udev:
-	wlr_udev_free(&state->udev);
-error_list:
 	list_free(state->outputs);
 error_backend:
 	free(state);

backend/udev.c

@@ -1,5 +1,4 @@
 #define _POSIX_C_SOURCE 200809L
-
 #include <libudev.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -8,13 +7,10 @@
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 #include <wayland-server.h>
-
 #include <wlr/session.h>
-
 #include "backend.h"
 #include "backend/drm/backend.h"
-#include "backend/drm/udev.h"
-#include "backend/drm/drm.h"
+#include "backend/udev.h"
 #include "common/log.h"
 
 /* Tests if 'path' is KMS compatible by trying to open it.
@@ -140,7 +136,6 @@ int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session) {
 
 static int udev_event(int fd, uint32_t mask, void *data) {
 	struct wlr_udev *udev = data;
-	struct wlr_backend_state *state = wl_container_of(udev, state, udev);
 
 	struct udev_device *dev = udev_monitor_receive_device(udev->mon);
 	if (!dev) {
@@ -161,19 +156,25 @@ static int udev_event(int fd, uint32_t mask, void *data) {
 		goto out;
 	}
 
-	wlr_drm_scan_connectors(state);
+	// TODO: Specify the GPU that's being invalidated
+	wl_signal_emit(&udev->invalidate_drm, udev);
 
 out:
 	udev_device_unref(dev);
 	return 1;
 }
 
-bool wlr_udev_init(struct wl_display *display, struct wlr_udev *udev) {
+struct wlr_udev *wlr_udev_create(struct wl_display *display) {
+	struct wlr_udev *udev = calloc(sizeof(struct wlr_udev), 1);
+	if (!udev) {
+		return NULL;
+	}
 	udev->udev = udev_new();
 	if (!udev->udev) {
 		wlr_log(L_ERROR, "Failed to create udev context");
-		return false;
+		goto error;
 	}
+	wl_signal_init(&udev->invalidate_drm);
 
 	udev->mon = udev_monitor_new_from_netlink(udev->udev, "udev");
 	if (!udev->mon) {
@@ -195,16 +196,18 @@ bool wlr_udev_init(struct wl_display *display, struct wlr_udev *udev) {
 	}
 	
 	wlr_log(L_DEBUG, "Successfully initialized udev");
-	return true;
+	return udev;
 
 error_mon:
 	udev_monitor_unref(udev->mon);
 error_udev:
 	udev_unref(udev->udev);
-	return false;
+error:
+	free(udev);
+	return NULL;
 }
 
-void wlr_udev_free(struct wlr_udev *udev) {
+void wlr_udev_destroy(struct wlr_udev *udev) {
 	if (!udev) {
 		return;
 	}

include/backend/drm/backend.h

@@ -13,7 +13,7 @@
 #include <wlr/backend/drm.h>
 
 #include "backend.h"
-#include "udev.h"
+#include "backend/udev.h"
 #include "event.h"
 #include "drm.h"
 
@@ -26,13 +26,14 @@ struct wlr_backend_state {
 
 	struct wl_listener device_paused;
 	struct wl_listener device_resumed;
+	struct wl_listener drm_invalidated;
 
 	uint32_t taken_crtcs;
 	list_t *outputs;
 
 	struct wlr_drm_renderer renderer;
 	struct wlr_session *session;
-	struct wlr_udev udev;
+	struct wlr_udev *udev;
 };
 
 #endif

include/backend/udev.h

@@ -1,24 +1,19 @@
-#ifndef UDEV_H
-#define UDEV_H
+#ifndef _WLR_INTERNAL_UDEV_H
+#define _WLR_INTERNAL_UDEV_H
 
 #include <libudev.h>
-
 #include <wlr/session.h>
 #include <wayland-server.h>
+#include <wlr/backend/udev.h>
 
 struct wlr_udev {
 	struct udev *udev;
 	struct udev_monitor *mon;
 	char *drm_path;
-
 	struct wl_event_source *event;
+	struct wl_signal invalidate_drm;
 };
 
-struct wlr_drm_backend;
-bool wlr_udev_init(struct wl_display *display, struct wlr_udev *udev);
-void wlr_udev_free(struct wlr_udev *udev);
 int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session);
 
-void wlr_udev_event(struct wlr_drm_backend *backend);
-
 #endif

include/wlr/backend/drm.h

@@ -4,8 +4,9 @@
 #include <wayland-server.h>
 #include <wlr/session.h>
 #include <wlr/backend.h>
+#include <wlr/backend/udev.h>
 
 struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
-	struct wlr_session *session);
+		struct wlr_session *session, struct wlr_udev *udev, int gpu_fd);
 
 #endif

include/wlr/backend/udev.h

@@ -0,0 +1,9 @@
+#ifndef _WLR_BACKEND_UDEV_H
+#define _WLR_BACKEND_UDEV_H
+
+struct wlr_udev;
+
+struct wlr_udev *wlr_udev_create(struct wl_display *display);
+void wlr_udev_destroy(struct wlr_udev *udev);
+
+#endif