backend/drm: get rid of wlr_drm_fb_type

Since all DRM FBs are backed by a wlr_buffer, there's no need for this
anymore.

backend/drm/drm.c

@@ -377,7 +377,7 @@ static bool drm_crtc_page_flip(struct wlr_drm_connector *conn) {
 	}
 
 	assert(crtc->pending.active);
-	assert(plane_get_next_fb(crtc->primary)->type != WLR_DRM_FB_TYPE_NONE);
+	assert(plane_get_next_fb(crtc->primary)->bo);
 	if (!drm_crtc_commit(conn, DRM_MODE_PAGE_FLIP_EVENT)) {
 		return false;
 	}
@@ -650,10 +650,10 @@ static bool drm_connector_export_dmabuf(struct wlr_output *output,
 	}
 
 	struct wlr_drm_fb *fb = &crtc->primary->queued_fb;
-	if (fb->type == WLR_DRM_FB_TYPE_NONE) {
+	if (fb->bo == NULL) {
 		fb = &crtc->primary->current_fb;
 	}
-	if (fb->type == WLR_DRM_FB_TYPE_NONE) {
+	if (fb->bo == NULL) {
 		return false;
 	}
 
@@ -661,10 +661,10 @@ static bool drm_connector_export_dmabuf(struct wlr_output *output,
 }
 
 struct wlr_drm_fb *plane_get_next_fb(struct wlr_drm_plane *plane) {
-	if (plane->pending_fb.type != WLR_DRM_FB_TYPE_NONE) {
+	if (plane->pending_fb.bo) {
 		return &plane->pending_fb;
 	}
-	if (plane->queued_fb.type != WLR_DRM_FB_TYPE_NONE) {
+	if (plane->queued_fb.bo) {
 		return &plane->queued_fb;
 	}
 	return &plane->current_fb;
@@ -680,7 +680,7 @@ static bool drm_connector_pageflip_renderer(struct wlr_drm_connector *conn) {
 
 	// drm_crtc_page_flip expects a FB to be available
 	struct wlr_drm_plane *plane = crtc->primary;
-	if (plane_get_next_fb(plane)->type == WLR_DRM_FB_TYPE_NONE) {
+	if (!plane_get_next_fb(plane)->bo) {
 		drm_surface_render_black_frame(&plane->surf);
 		if (!drm_fb_lock_surface(&plane->pending_fb, &plane->surf)) {
 			return false;
@@ -1507,11 +1507,10 @@ static void page_flip_handler(int fd, unsigned seq,
 	}
 
 	struct wlr_drm_plane *plane = conn->crtc->primary;
-	if (plane->queued_fb.type != WLR_DRM_FB_TYPE_NONE) {
+	if (plane->queued_fb.bo) {
 		drm_fb_move(&plane->current_fb, &plane->queued_fb);
 	}
-	if (conn->crtc->cursor &&
-			conn->crtc->cursor->queued_fb.type != WLR_DRM_FB_TYPE_NONE) {
+	if (conn->crtc->cursor && conn->crtc->cursor->queued_fb.bo) {
 		drm_fb_move(&conn->crtc->cursor->current_fb,
 			&conn->crtc->cursor->queued_fb);
 	}
@@ -1522,7 +1521,8 @@ static void page_flip_handler(int fd, unsigned seq,
 	 * data between the GPUs, even if we were using the direct scanout
 	 * interface.
 	 */
-	if (!drm->parent && plane->current_fb.type == WLR_DRM_FB_TYPE_WLR_BUFFER) {
+	if (!drm->parent && plane->current_fb.wlr_buf &&
+			wlr_client_buffer_get(plane->current_fb.wlr_buf)) {
 		present_flags |= WLR_OUTPUT_PRESENT_ZERO_COPY;
 	}
 

backend/drm/renderer.c

@@ -280,21 +280,15 @@ bool drm_plane_init_surface(struct wlr_drm_plane *plane,
 }
 
 void drm_fb_clear(struct wlr_drm_fb *fb) {
-	switch (fb->type) {
-	case WLR_DRM_FB_TYPE_NONE:
-		assert(!fb->bo);
-		break;
-	case WLR_DRM_FB_TYPE_SURFACE:
-		abort(); // TODO: remove this case entirely
-		break;
-	case WLR_DRM_FB_TYPE_WLR_BUFFER:
-		gbm_bo_destroy(fb->bo);
-		wlr_buffer_unlock(fb->wlr_buf);
-		fb->wlr_buf = NULL;
-		break;
-	}
-
-	fb->type = WLR_DRM_FB_TYPE_NONE;
+	if (!fb->bo) {
+		assert(!fb->wlr_buf);
+		return;
+	}
+
+	gbm_bo_destroy(fb->bo);
+	wlr_buffer_unlock(fb->wlr_buf);
+
+	fb->wlr_buf = NULL;
 	fb->bo = NULL;
 
 	if (fb->mgpu_bo) {
@@ -376,7 +370,6 @@ bool drm_fb_import_wlr(struct wlr_drm_fb *fb, struct wlr_drm_renderer *renderer,
 		return false;
 	}
 
-	fb->type = WLR_DRM_FB_TYPE_WLR_BUFFER;
 	fb->wlr_buf = wlr_buffer_lock(buf);
 
 	return true;

include/backend/drm/renderer.h

@@ -33,20 +33,12 @@ struct wlr_drm_surface {
 	struct wlr_buffer *back_buffer;
 };
 
-enum wlr_drm_fb_type {
-	WLR_DRM_FB_TYPE_NONE,
-	WLR_DRM_FB_TYPE_SURFACE,
-	WLR_DRM_FB_TYPE_WLR_BUFFER
-};
-
 struct wlr_drm_fb {
-	enum wlr_drm_fb_type type;
 	struct gbm_bo *bo;
+	struct wlr_buffer *wlr_buf;
 
 	struct wlr_drm_surface *mgpu_surf;
 	struct gbm_bo *mgpu_bo;
-
-	struct wlr_buffer *wlr_buf;
 };
 
 bool init_drm_renderer(struct wlr_drm_backend *drm,