backend/drm: introduce pending and current CRTC state

Previously, we only had the pending state (crtc->pending, crtc->mode and
crtc->active). This causes issues when a commit fails: the pending state
is left as-is, and the next commit may read stale data from it.

This will also cause issues when implementing test-only commits: we need
to rollback the pending CRTC state after a test-only commit.

Introduce separate pending and current CRTC states. Properly update the
current state after a commit.

1 files changed, 5 insertions, 5 deletions

diff --git a/include/backend/drm/drm.h b/include/backend/drm/drm.h
index dc34c681..7755da59 100644
--- a/include/backend/drm/drm.h
+++ b/include/backend/drm/drm.h
@@ -42,16 +42,16 @@ struct wlr_drm_plane {
 	union wlr_drm_plane_props props;
 };
 
-enum wlr_drm_crtc_field {
-	WLR_DRM_CRTC_MODE = 1 << 0,
+struct wlr_drm_crtc_state {
+	bool active;
+	struct wlr_drm_mode *mode;
 };
 
 struct wlr_drm_crtc {
 	uint32_t id;
-	uint32_t pending; // bitfield of enum wlr_drm_crtc_field
 
-	bool active;
-	drmModeModeInfo mode;
+	bool pending_modeset;
+	struct wlr_drm_crtc_state pending, current;
 
 	// Atomic modesetting only
 	uint32_t mode_id;