backend/drm: remove wlr_drm_crtc_state.mode

Replace it with drm_connector_state_mode, which computes the mode
from the wlr_output_state to be applied.

backend/drm/atomic.c

@@ -62,7 +62,9 @@ static bool create_mode_blob(struct wlr_drm_backend *drm,
 		return true;
 	}
 
-	if (drmModeCreatePropertyBlob(drm->fd, &conn->crtc->pending.mode->drm_mode,
+	drmModeModeInfo mode = {0};
+	drm_connector_state_mode(conn, state, &mode);
+	if (drmModeCreatePropertyBlob(drm->fd, &mode,
 			sizeof(drmModeModeInfo), blob_id)) {
 		wlr_log_errno(WLR_ERROR, "Unable to create mode property blob");
 		return false;

backend/drm/drm.c

@@ -333,13 +333,11 @@ static bool drm_crtc_commit(struct wlr_drm_connector *conn,
 	struct wlr_drm_crtc *crtc = conn->crtc;
 	bool ok = drm->iface->crtc_commit(drm, conn, state, flags);
 	if (ok && !(flags & DRM_MODE_ATOMIC_TEST_ONLY)) {
-		memcpy(&crtc->current, &crtc->pending, sizeof(struct wlr_drm_crtc_state));
 		drm_plane_set_committed(crtc->primary);
 		if (crtc->cursor != NULL) {
 			drm_plane_set_committed(crtc->cursor);
 		}
 	} else {
-		memcpy(&crtc->pending, &crtc->current, sizeof(struct wlr_drm_crtc_state));
 		drm_fb_clear(&crtc->primary->pending_fb);
 		if (crtc->cursor != NULL) {
 			drm_fb_clear(&crtc->cursor->pending_fb);
@@ -438,10 +436,7 @@ static struct wlr_output_mode *drm_connector_get_pending_mode(
 		return output->pending.mode;
 	case WLR_OUTPUT_STATE_MODE_CUSTOM:;
 		drmModeModeInfo mode = {0};
-		generate_cvt_mode(&mode, output->pending.custom_mode.width,
+		drm_connector_state_mode(conn, &output->pending, &mode);
-			output->pending.custom_mode.height,
-			(float)output->pending.custom_mode.refresh / 1000, false, false);
-		mode.type = DRM_MODE_TYPE_USERDEF;
 		return wlr_drm_connector_add_mode(output, &mode);
 	}
 	abort();
@@ -680,8 +675,6 @@ static bool drm_connector_init_renderer(struct wlr_drm_connector *conn,
 	}
 	struct wlr_drm_plane *plane = crtc->primary;
 
-	crtc->pending.mode = mode;
-
 	int width = mode->wlr_mode.width;
 	int height = mode->wlr_mode.height;
 	uint32_t format = DRM_FORMAT_ARGB8888;
@@ -702,8 +695,6 @@ static bool drm_connector_init_renderer(struct wlr_drm_connector *conn,
 			"retrying without modifiers");
 		modifiers = false;
 
-		crtc->pending.mode = mode;
-
 		if (!drm_plane_init_surface(plane, drm, width, height, format,
 				modifiers)) {
 			return false;
@@ -1047,6 +1038,31 @@ bool drm_connector_state_active(struct wlr_drm_connector *conn,
 	return conn->output.enabled;
 }
 
+void drm_connector_state_mode(struct wlr_drm_connector *conn,
+		const struct wlr_output_state *state, drmModeModeInfo *out) {
+	assert(drm_connector_state_active(conn, state));
+
+	struct wlr_output_mode *wlr_mode = conn->output.current_mode;
+	if (state->committed & WLR_OUTPUT_STATE_MODE) {
+		switch (state->mode_type) {
+		case WLR_OUTPUT_STATE_MODE_FIXED:
+			wlr_mode = state->mode;
+			break;
+		case WLR_OUTPUT_STATE_MODE_CUSTOM:;
+			drmModeModeInfo mode = {0};
+			generate_cvt_mode(&mode, state->custom_mode.width,
+				state->custom_mode.height,
+				(float)state->custom_mode.refresh / 1000, false, false);
+			mode.type = DRM_MODE_TYPE_USERDEF;
+			memcpy(out, &mode, sizeof(drmModeModeInfo));
+			return;
+		}
+	}
+
+	struct wlr_drm_mode *mode = (struct wlr_drm_mode *)wlr_mode;
+	memcpy(out, &mode->drm_mode, sizeof(drmModeModeInfo));
+}
+
 static const int32_t subpixel_map[] = {
 	[DRM_MODE_SUBPIXEL_UNKNOWN] = WL_OUTPUT_SUBPIXEL_UNKNOWN,
 	[DRM_MODE_SUBPIXEL_HORIZONTAL_RGB] = WL_OUTPUT_SUBPIXEL_HORIZONTAL_RGB,

backend/drm/legacy.c

@@ -32,10 +32,12 @@ static bool legacy_crtc_commit(struct wlr_drm_backend *drm,
 		uint32_t *conns = NULL;
 		size_t conns_len = 0;
 		drmModeModeInfo *mode = NULL;
+		drmModeModeInfo mode_info = {0};
 		if (active) {
 			conns = &conn->id;
 			conns_len = 1;
-			mode = &crtc->pending.mode->drm_mode;
+			drm_connector_state_mode(conn, state, &mode_info);
+			mode = &mode_info;
 		}
 
 		uint32_t dpms = active ? DRM_MODE_DPMS_ON : DRM_MODE_DPMS_OFF;

include/backend/drm/drm.h

@@ -41,15 +41,9 @@ struct wlr_drm_plane {
 	union wlr_drm_plane_props props;
 };
 
-struct wlr_drm_crtc_state {
-	struct wlr_drm_mode *mode;
-};
-
 struct wlr_drm_crtc {
 	uint32_t id;
 
-	struct wlr_drm_crtc_state pending, current;
-
 	// Atomic modesetting only
 	uint32_t mode_id;
 	uint32_t gamma_lut;
@@ -161,6 +155,8 @@ struct wlr_drm_fb *plane_get_next_fb(struct wlr_drm_plane *plane);
 bool drm_connector_state_is_modeset(const struct wlr_output_state *state);
 bool drm_connector_state_active(struct wlr_drm_connector *conn,
 	const struct wlr_output_state *state);
+void drm_connector_state_mode(struct wlr_drm_connector *conn,
+	const struct wlr_output_state *state, drmModeModeInfo *mode);
 
 #define wlr_drm_conn_log(conn, verb, fmt, ...) \
 	wlr_log(verb, "connector %s: " fmt, conn->name, ##__VA_ARGS__)