backend/drm: make drm_fb_acquire return a FB ID

backend/drm/atomic.c

@@ -135,12 +135,7 @@ static void set_plane_props(struct atomic *atom, struct wlr_drm_backend *drm,
 	uint32_t id = plane->id;
 	const union wlr_drm_plane_props *props = &plane->props;
 	struct wlr_drm_fb *fb = plane_get_next_fb(plane);
-	struct gbm_bo *bo = drm_fb_acquire(fb, drm, &plane->mgpu_surf);
+	uint32_t fb_id = drm_fb_acquire(fb, drm, &plane->mgpu_surf);
-	if (!bo) {
-		goto error;
-	}
-
-	uint32_t fb_id = get_fb_for_bo(bo, drm->addfb2_modifiers);
 	if (!fb_id) {
 		goto error;
 	}

backend/drm/legacy.c

@@ -17,12 +17,7 @@ static bool legacy_crtc_commit(struct wlr_drm_backend *drm,
 	uint32_t fb_id = 0;
 	if (crtc->pending.active) {
 		struct wlr_drm_fb *fb = plane_get_next_fb(crtc->primary);
-		struct gbm_bo *bo = drm_fb_acquire(fb, drm, &crtc->primary->mgpu_surf);
+		uint32_t fb_id = drm_fb_acquire(fb, drm, &crtc->primary->mgpu_surf);
-		if (!bo) {
-			return false;
-		}
-
-		fb_id = get_fb_for_bo(bo, drm->addfb2_modifiers);
 		if (!fb_id) {
 			return false;
 		}
@@ -79,14 +74,17 @@ static bool legacy_crtc_commit(struct wlr_drm_backend *drm,
 
 	if (cursor != NULL && drm_connector_is_cursor_visible(conn)) {
 		struct wlr_drm_fb *cursor_fb = plane_get_next_fb(cursor);
-		struct gbm_bo *cursor_bo =
+		if (drm_fb_acquire(cursor_fb, drm, &cursor->mgpu_surf) == 0) {
-			drm_fb_acquire(cursor_fb, drm, &cursor->mgpu_surf);
-		if (!cursor_bo) {
 			wlr_drm_conn_log_errno(conn, WLR_DEBUG,
 				"Failed to acquire cursor FB");
 			return false;
 		}
 
+		struct gbm_bo *cursor_bo = cursor_fb->bo;
+		if (cursor_fb->mgpu_bo) {
+			cursor_bo = cursor_fb->mgpu_bo;
+		}
+
 		if (drmModeSetCursor(drm->fd, crtc->id,
 				gbm_bo_get_handle(cursor_bo).u32,
 				cursor->surf.width, cursor->surf.height)) {

backend/drm/renderer.c

@@ -14,6 +14,7 @@
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/util/log.h>
 #include "backend/drm/drm.h"
+#include "backend/drm/util.h"
 #include "render/drm_format_set.h"
 #include "render/gbm_allocator.h"
 #include "render/swapchain.h"
@@ -248,6 +249,14 @@ void drm_fb_clear(struct wlr_drm_fb *fb) {
 		return;
 	}
 
+	struct gbm_device *gbm = gbm_bo_get_device(fb->bo);
+	if (fb->mgpu_bo) {
+		gbm = gbm_bo_get_device(fb->mgpu_bo);
+	}
+	if (drmModeRmFB(gbm_device_get_fd(gbm), fb->id) != 0) {
+		wlr_log(WLR_ERROR, "drmModeRmFB failed");
+	}
+
 	gbm_bo_destroy(fb->bo);
 	wlr_buffer_unlock(fb->wlr_buf);
 
@@ -362,19 +371,20 @@ bool drm_surface_render_black_frame(struct wlr_drm_surface *surf) {
 	return true;
 }
 
-struct gbm_bo *drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm,
+uint32_t drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm,
 		struct wlr_drm_surface *mgpu) {
+	if (fb->id) {
+		return fb->id;
+	}
+
 	if (!fb->bo) {
 		wlr_log(WLR_ERROR, "Tried to acquire an FB with a NULL BO");
-		return NULL;
+		return 0;
 	}
 
 	if (!drm->parent) {
-		return fb->bo;
+		fb->id = get_fb_for_bo(fb->bo, drm->addfb2_modifiers);
-	}
+		return fb->id;
-
-	if (fb->mgpu_bo) {
-		return fb->mgpu_bo;
 	}
 
 	/* Perform copy across GPUs */
@@ -383,17 +393,17 @@ struct gbm_bo *drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm
 
 	struct wlr_dmabuf_attributes attribs = {0};
 	if (!wlr_buffer_get_dmabuf(fb->wlr_buf, &attribs)) {
-		return NULL;
+		return 0;
 	}
 
 	struct wlr_texture *tex = wlr_texture_from_dmabuf(renderer, &attribs);
 	if (tex == NULL) {
-		return NULL;
+		return 0;
 	}
 
 	if (!drm_surface_make_current(mgpu, NULL)) {
 		wlr_texture_destroy(tex);
-		return NULL;
+		return 0;
 	}
 
 	float mat[9];
@@ -410,7 +420,7 @@ struct gbm_bo *drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm
 	};
 	if (!drm_fb_lock_surface(&mgpu_fb, mgpu)) {
 		wlr_texture_destroy(tex);
-		return false;
+		return 0;
 	}
 
 	wlr_texture_destroy(tex);
@@ -418,5 +428,7 @@ struct gbm_bo *drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm
 	fb->mgpu_bo = mgpu_fb.bo;
 	fb->mgpu_wlr_buf = mgpu_fb.wlr_buf;
 	fb->mgpu_surf = mgpu;
-	return fb->mgpu_bo;
+
+	fb->id = get_fb_for_bo(fb->mgpu_bo, drm->addfb2_modifiers);
+	return fb->id;
 }

backend/drm/util.c

@@ -170,21 +170,7 @@ const char *conn_get_name(uint32_t type_id) {
 	}
 }
 
-static void free_fb(struct gbm_bo *bo, void *data) {
-	uint32_t id = (uintptr_t)data;
-
-	if (id) {
-		struct gbm_device *gbm = gbm_bo_get_device(bo);
-		drmModeRmFB(gbm_device_get_fd(gbm), id);
-	}
-}
-
 uint32_t get_fb_for_bo(struct gbm_bo *bo, bool with_modifiers) {
-	uint32_t id = (uintptr_t)gbm_bo_get_user_data(bo);
-	if (id) {
-		return id;
-	}
-
 	struct gbm_device *gbm = gbm_bo_get_device(bo);
 
 	int fd = gbm_device_get_fd(gbm);
@@ -204,6 +190,7 @@ uint32_t get_fb_for_bo(struct gbm_bo *bo, bool with_modifiers) {
 		modifiers[i] = gbm_bo_get_modifier(bo);
 	}
 
+	uint32_t id = 0;
 	if (with_modifiers && gbm_bo_get_modifier(bo) != DRM_FORMAT_MOD_INVALID) {
 		if (drmModeAddFB2WithModifiers(fd, width, height, format, handles,
 				strides, offsets, modifiers, &id, DRM_MODE_FB_MODIFIERS)) {
@@ -216,8 +203,6 @@ uint32_t get_fb_for_bo(struct gbm_bo *bo, bool with_modifiers) {
 		}
 	}
 
-	gbm_bo_set_user_data(bo, (void *)(uintptr_t)id, free_fb);
-
 	return id;
 }
 

include/backend/drm/renderer.h

@@ -38,6 +38,8 @@ struct wlr_drm_fb {
 	struct wlr_drm_surface *mgpu_surf;
 	struct gbm_bo *mgpu_bo;
 	struct wlr_buffer *mgpu_wlr_buf;
+
+	uint32_t id;
 };
 
 bool init_drm_renderer(struct wlr_drm_backend *drm,
@@ -55,7 +57,7 @@ bool drm_fb_import_wlr(struct wlr_drm_fb *fb, struct wlr_drm_renderer *renderer,
 void drm_fb_move(struct wlr_drm_fb *new, struct wlr_drm_fb *old);
 
 bool drm_surface_render_black_frame(struct wlr_drm_surface *surf);
-struct gbm_bo *drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm,
+uint32_t drm_fb_acquire(struct wlr_drm_fb *fb, struct wlr_drm_backend *drm,
 		struct wlr_drm_surface *mgpu);
 
 bool drm_plane_init_surface(struct wlr_drm_plane *plane,