backend/drm: introduce wlr_drm_connector_state

Previously, we were copying wlr_output_state on the stack and
patching it up to be guaranteed to have a proper drmModeModeInfo
stored in it (and not a custom mode). Also, we had a bunch of
helpers deriving DRM-specific information from the generic
wlr_output_state.

Copying the wlr_output_state worked fine so far, but with output
layers we'll be getting a wl_list in there. An empty wl_list stores
two pointers to itself, copying it on the stack blindly results in
infinite loops in wl_list_for_each.

To fix this, rework our DRM backend to stop copying wlr_output_state,
instead add a new struct wlr_drm_connector_state which holds both
the wlr_output_state and additional DRM-specific information.

1 files changed, 17 insertions, 18 deletions

diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c
index ba493f6f..70f55aff 100644
--- a/backend/drm/atomic.c
+++ b/backend/drm/atomic.c
@@ -54,16 +54,14 @@ static void atomic_add(struct atomic *atom, uint32_t id, uint32_t prop, uint64_t
 }
 
 static bool create_mode_blob(struct wlr_drm_backend *drm,
-		struct wlr_drm_connector *conn, const struct wlr_output_state *state,
-		uint32_t *blob_id) {
-	if (!drm_connector_state_active(conn, state)) {
+		struct wlr_drm_connector *conn,
+		const struct wlr_drm_connector_state *state, uint32_t *blob_id) {
+	if (!state->active) {
 		*blob_id = 0;
 		return true;
 	}
 
-	drmModeModeInfo mode = {0};
-	drm_connector_state_mode(conn, state, &mode);
-	if (drmModeCreatePropertyBlob(drm->fd, &mode,
+	if (drmModeCreatePropertyBlob(drm->fd, &state->mode,
 			sizeof(drmModeModeInfo), blob_id)) {
 		wlr_log_errno(WLR_ERROR, "Unable to create mode property blob");
 		return false;
@@ -166,13 +164,14 @@ error:
 }
 
 static bool atomic_crtc_commit(struct wlr_drm_connector *conn,
-		const struct wlr_output_state *state, uint32_t flags, bool test_only) {
+		const struct wlr_drm_connector_state *state, uint32_t flags,
+		bool test_only) {
 	struct wlr_drm_backend *drm = conn->backend;
 	struct wlr_output *output = &conn->output;
 	struct wlr_drm_crtc *crtc = conn->crtc;
 
-	bool modeset = drm_connector_state_is_modeset(state);
-	bool active = drm_connector_state_active(conn, state);
+	bool modeset = state->modeset;
+	bool active = state->active;
 
 	uint32_t mode_id = crtc->mode_id;
 	if (modeset) {
@@ -182,30 +181,30 @@ static bool atomic_crtc_commit(struct wlr_drm_connector *conn,
 	}
 
 	uint32_t gamma_lut = crtc->gamma_lut;
-	if (state->committed & WLR_OUTPUT_STATE_GAMMA_LUT) {
+	if (state->base->committed & WLR_OUTPUT_STATE_GAMMA_LUT) {
 		// Fallback to legacy gamma interface when gamma properties are not
 		// available (can happen on older Intel GPUs that support gamma but not
 		// degamma).
 		if (crtc->props.gamma_lut == 0) {
 			if (!drm_legacy_crtc_set_gamma(drm, crtc,
-					state->gamma_lut_size,
-					state->gamma_lut)) {
+					state->base->gamma_lut_size,
+					state->base->gamma_lut)) {
 				return false;
 			}
 		} else {
-			if (!create_gamma_lut_blob(drm, state->gamma_lut_size,
-					state->gamma_lut, &gamma_lut)) {
+			if (!create_gamma_lut_blob(drm, state->base->gamma_lut_size,
+					state->base->gamma_lut, &gamma_lut)) {
 				return false;
 			}
 		}
 	}
 
 	uint32_t fb_damage_clips = 0;
-	if ((state->committed & WLR_OUTPUT_STATE_DAMAGE) &&
+	if ((state->base->committed & WLR_OUTPUT_STATE_DAMAGE) &&
 			crtc->primary->props.fb_damage_clips != 0) {
 		int rects_len;
 		const pixman_box32_t *rects = pixman_region32_rectangles(
-			(pixman_region32_t *)&state->damage, &rects_len);
+			(pixman_region32_t *)&state->base->damage, &rects_len);
 		if (drmModeCreatePropertyBlob(drm->fd, rects,
 				sizeof(*rects) * rects_len, &fb_damage_clips) != 0) {
 			wlr_log_errno(WLR_ERROR, "Failed to create FB_DAMAGE_CLIPS property blob");
@@ -215,9 +214,9 @@ static bool atomic_crtc_commit(struct wlr_drm_connector *conn,
 	bool prev_vrr_enabled =
 		output->adaptive_sync_status == WLR_OUTPUT_ADAPTIVE_SYNC_ENABLED;
 	bool vrr_enabled = prev_vrr_enabled;
-	if ((state->committed & WLR_OUTPUT_STATE_ADAPTIVE_SYNC_ENABLED) &&
+	if ((state->base->committed & WLR_OUTPUT_STATE_ADAPTIVE_SYNC_ENABLED) &&
 			drm_connector_supports_vrr(conn)) {
-		vrr_enabled = state->adaptive_sync_enabled;
+		vrr_enabled = state->base->adaptive_sync_enabled;
 	}
 
 	if (test_only) {