diff --git a/src/backend/driver.c b/src/backend/driver.c
index 3be7215693..f17743a4aa 100644
--- a/src/backend/driver.c
+++ b/src/backend/driver.c
@@ -20,7 +20,7 @@ void apply_driver_workarounds(struct session *ps, enum driver driver) {
 }
 
 enum vblank_scheduler_type choose_vblank_scheduler(enum driver driver) {
-	if (driver & DRIVER_INTEL) {
+	if (driver & DRIVER_NVIDIA) {
 		return VBLANK_SCHEDULER_SGI_VIDEO_SYNC;
 	}
 	return VBLANK_SCHEDULER_PRESENT;
diff --git a/src/common.h b/src/common.h
index 6876c24a72..273e399188 100644
--- a/src/common.h
+++ b/src/common.h
@@ -134,17 +134,6 @@ struct shader_info {
 	UT_hash_handle hh;
 };
 
-enum render_progress {
-	/// Render is finished and presented to the screen.
-	RENDER_IDLE = 0,
-	/// Rendering is queued, but not started yet.
-	RENDER_QUEUED,
-	/// Backend has been called, render commands have been issued.
-	RENDER_STARTED,
-	/// Backend reported render commands have been finished. (not actually used).
-	RENDER_FINISHED,
-};
-
 /// Structure containing all necessary data for a session.
 typedef struct session {
 	// === Event handlers ===
diff --git a/src/config.c b/src/config.c
index 37dc4586d8..076fe1ec62 100644
--- a/src/config.c
+++ b/src/config.c
@@ -624,10 +624,14 @@ struct debug_options_entry {
 };
 
 // clang-format off
-static const char *vblank_scheduler_choices[] = { "present", "sgi_video_sync", NULL };
+const char *vblank_scheduler_str[] = {
+	[VBLANK_SCHEDULER_PRESENT] = "present",
+	[VBLANK_SCHEDULER_SGI_VIDEO_SYNC] = "sgi_video_sync",
+	[LAST_VBLANK_SCHEDULER] = NULL
+};
 static const struct debug_options_entry debug_options_entries[] = {
-    {"smart_frame_pacing", NULL,                     offsetof(struct debug_options, smart_frame_pacing)},
-    {"force_vblank_sched", vblank_scheduler_choices, offsetof(struct debug_options, force_vblank_scheduler)},
+    {"smart_frame_pacing", NULL,                 offsetof(struct debug_options, smart_frame_pacing)},
+    {"force_vblank_sched", vblank_scheduler_str, offsetof(struct debug_options, force_vblank_scheduler)},
 };
 // clang-format on
 
@@ -655,11 +659,14 @@ void parse_debug_option_single(char *setting, struct debug_options *debug_option
 			}
 			if (!parse_int(arg, value)) {
 				log_error("Invalid value for debug option %s: %s, it "
-				          "will be ignored",
-				          setting, arg);
+				          "will be ignored.",
+				          debug_options_entries[i].name, arg);
 			}
-		} else {
+		} else if (debug_options_entries[i].choices == NULL) {
 			*value = 1;
+		} else {
+			log_error(
+			    "Missing value for debug option %s, it will be ignored.", setting);
 		}
 		return;
 	}
diff --git a/src/config.h b/src/config.h
index 226a692c54..0a736d3faf 100644
--- a/src/config.h
+++ b/src/config.h
@@ -103,13 +103,7 @@ enum vblank_scheduler_type {
 	LAST_VBLANK_SCHEDULER,
 };
 
-static inline const char *vblank_scheduler_type_str(enum vblank_scheduler_type type) {
-	switch (type) {
-	case VBLANK_SCHEDULER_PRESENT: return "present";
-	case VBLANK_SCHEDULER_SGI_VIDEO_SYNC: return "sgi_video_sync";
-	default: return "invalid";
-	}
-}
+extern const char *vblank_scheduler_str[];
 
 /// Internal, private options for debugging and development use.
 struct debug_options {
diff --git a/src/picom.c b/src/picom.c
index 78faf846e3..bdf4bbc028 100644
--- a/src/picom.c
+++ b/src/picom.c
@@ -227,9 +227,9 @@ void collect_vblank_interval_statistics(struct vblank_event *e, void *ud) {
 
 void schedule_render(session_t *ps, bool triggered_by_vblank);
 
-/// vblank callback scheduled by schedule_render.
+/// vblank callback scheduled by schedule_render, when a render is ongoing.
 ///
-/// Check if previously queued render has finished, and record the time it took.
+/// Check if previously queued render has finished, and reschedule render if it has.
 void reschedule_render_at_vblank(struct vblank_event *e, void *ud) {
 	auto ps = (session_t *)ud;
 	assert(ps->frame_pacing);
@@ -1675,8 +1675,7 @@ static bool redirect_start(session_t *ps) {
 			scheduler_type =
 			    (enum vblank_scheduler_type)ps->o.debug_options.force_vblank_scheduler;
 		}
-		log_info("Using vblank scheduler: %s.",
-		         vblank_scheduler_type_str(scheduler_type));
+		log_info("Using vblank scheduler: %s.", vblank_scheduler_str[scheduler_type]);
 		ps->vblank_scheduler = vblank_scheduler_new(
 		    ps->loop, &ps->c, session_get_target_window(ps), scheduler_type);
 		if (!ps->vblank_scheduler) {
diff --git a/src/vblank.c b/src/vblank.c
index cbfc18c187..fb9b0672f9 100644
--- a/src/vblank.c
+++ b/src/vblank.c
@@ -7,6 +7,7 @@
 #include <time.h>
 #include <xcb/xcb.h>
 #include <xcb/xproto.h>
+#include "config.h"
 
 #ifdef CONFIG_OPENGL
 // Enable sgi_video_sync_vblank_scheduler
@@ -526,4 +527,4 @@ bool vblank_handle_x_events(struct vblank_scheduler *self) {
 		return fn(self);
 	}
 	return true;
-}
\ No newline at end of file
+}