diff --git a/lib/libusb/libusb.h b/lib/libusb/libusb.h
--- a/lib/libusb/libusb.h
+++ b/lib/libusb/libusb.h
@@ -243,17 +243,6 @@
        LIBUSB_LOG_LEVEL_DEBUG
 };
 
-/* XXX */
-/* libusb_set_debug should take parameters from libusb_log_level
- * above according to
- *   https://libusb.sourceforge.io/api-1.0/group__libusb__lib.html
- */
-enum libusb_debug_level {
-	LIBUSB_DEBUG_NO=0,
-	LIBUSB_DEBUG_FUNCTION=1,
-	LIBUSB_DEBUG_TRANSFER=2,
-};
-
 #define	LIBUSB_HOTPLUG_MATCH_ANY -1
 
 typedef enum {
diff --git a/lib/libusb/libusb10.h b/lib/libusb/libusb10.h
--- a/lib/libusb/libusb10.h
+++ b/lib/libusb/libusb10.h
@@ -48,15 +48,27 @@
 
 #define	DPRINTF(ctx, dbg, format, ...) do {			\
 	switch (dbg) {						\
-	case LIBUSB_DEBUG_FUNCTION:				\
-		if ((ctx)->debug & LIBUSB_DEBUG_FUNCTION) {	\
-			printf("LIBUSB_FUNCTION: "		\
+	case LIBUSB_LOG_LEVEL_ERROR:							\
+		if ((ctx)->debug >= LIBUSB_LOG_LEVEL_ERROR) { 	\
+			printf("LIBUSB_ERROR: "		\
 			       format "\n", ## __VA_ARGS__);	\
 		}						\
 		break;						\
-	case LIBUSB_DEBUG_TRANSFER:				\
-		if ((ctx)->debug & LIBUSB_DEBUG_TRANSFER) { 	\
-			printf("LIBUSB_TRANSFER: "		\
+	case LIBUSB_LOG_LEVEL_WARNING:				\
+		if ((ctx)->debug >= LIBUSB_LOG_LEVEL_WARNING) {	\
+			printf("LIBUSB_WARN: "		\
+			       format "\n", ## __VA_ARGS__);	\
+		}						\
+		break;						\
+	case LIBUSB_LOG_LEVEL_INFO:				\
+		if ((ctx)->debug >= LIBUSB_LOG_LEVEL_INFO) { 	\
+			printf("LIBUSB_INFO: "		\
+			       format "\n", ## __VA_ARGS__);	\
+		}						\
+		break;						\
+	case LIBUSB_LOG_LEVEL_DEBUG:							\
+		if ((ctx)->debug >= LIBUSB_LOG_LEVEL_DEBUG) { 	\
+			printf("LIBUSB_DEBUG: "		\
 			       format "\n", ## __VA_ARGS__);	\
 		}						\
 		break;						\
diff --git a/lib/libusb/libusb10.c b/lib/libusb/libusb10.c
--- a/lib/libusb/libusb10.c
+++ b/lib/libusb/libusb10.c
@@ -127,7 +127,7 @@
 	err = eventfd_write(ctx->event, 1);
 	if (err < 0) {
 		/* ignore error, if any */
-		DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "Waking up event loop failed!");
+		DPRINTF(ctx, LIBUSB_LOG_LEVEL_ERROR, "Waking up event loop failed!");
 	}
 }
 
@@ -252,7 +252,7 @@
 	if (context)
 		*context = ctx;
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_init complete");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_INFO, "libusb_init complete");
 
 	signal(SIGPIPE, SIG_IGN);
 
@@ -601,7 +601,7 @@
 	if (ctx == NULL)
 		return (NULL);		/* be NULL safe */
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_open_device_with_vid_pid enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_open_device_with_vid_pid enter");
 
 	if ((i = libusb_get_device_list(ctx, &devs)) < 0)
 		return (NULL);
@@ -625,7 +625,7 @@
 	}
 
 	libusb_free_device_list(devs, 1);
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_open_device_with_vid_pid leave");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_open_device_with_vid_pid leave");
 	return (pdev);
 }
 
@@ -1506,7 +1506,7 @@
 
 	dev = libusb_get_device(uxfer->dev_handle);
 
-	DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_submit_transfer enter");
+	DPRINTF(dev->ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_submit_transfer enter");
 
 	sxfer = (struct libusb_super_transfer *)(
 	    (uint8_t *)uxfer - sizeof(*sxfer));
@@ -1541,7 +1541,7 @@
 
 	CTX_UNLOCK(dev->ctx);
 
-	DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_submit_transfer leave %d", err);
+	DPRINTF(dev->ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_submit_transfer leave %d", err);
 
 	return (err);
 }
@@ -1570,7 +1570,7 @@
 
 	dev = libusb_get_device(devh);
 
-	DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_cancel_transfer enter");
+	DPRINTF(dev->ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_cancel_transfer enter");
 
 	sxfer = (struct libusb_super_transfer *)(
 	    (uint8_t *)uxfer - sizeof(*sxfer));
@@ -1631,7 +1631,7 @@
 
 	CTX_UNLOCK(dev->ctx);
 
-	DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_cancel_transfer leave");
+	DPRINTF(dev->ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_cancel_transfer leave");
 
 	return (retval);
 }
diff --git a/lib/libusb/libusb10_io.c b/lib/libusb/libusb10_io.c
--- a/lib/libusb/libusb10_io.c
+++ b/lib/libusb/libusb10_io.c
@@ -108,7 +108,7 @@
 	int i;
 	int err;
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb10_handle_events_sub enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb10_handle_events_sub enter");
 
 	nfds = 0;
 	i = 0;
@@ -230,7 +230,7 @@
 
 	/* Wakeup other waiters */
 	pthread_cond_broadcast(&ctx->ctx_cond);
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb10_handle_events_sub complete");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb10_handle_events_sub complete");
 
 	return (err);
 }
@@ -314,7 +314,7 @@
 	int err;
 
 	ctx = GET_CONTEXT(ctx);
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_wait_for_event enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_wait_for_event enter");
 
 	if (tv == NULL) {
 		pthread_cond_wait(&ctx->ctx_cond,
@@ -358,7 +358,7 @@
 
 	ctx = GET_CONTEXT(ctx);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_handle_events_timeout_completed enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_handle_events_timeout_completed enter");
 
 	libusb_lock_events(ctx);
 
@@ -374,7 +374,7 @@
 
 	libusb_unlock_events(ctx);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_handle_events_timeout_completed exit");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_handle_events_timeout_completed exit");
 
 	return (err);
 }
@@ -523,7 +523,7 @@
 
 	ctx = libusb10_get_context_by_device_handle(transfer->dev_handle);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_TRANSFER, "sync I/O done");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "sync I/O done");
 
 	pdone = transfer->user_data;
 	*pdone = 1;
@@ -613,12 +613,12 @@
 
 	ctx = libusb10_get_context_by_device_handle(devh);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_bulk_transfer enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_bulk_transfer enter");
 
 	ret = libusb10_do_transfer(devh, endpoint, data, length, transferred,
 	    timeout, LIBUSB_TRANSFER_TYPE_BULK);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_bulk_transfer leave");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_bulk_transfer leave");
 	return (ret);
 }
 
@@ -632,12 +632,12 @@
 
 	ctx = libusb10_get_context_by_device_handle(devh);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_interrupt_transfer enter");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_interrupt_transfer enter");
 
 	ret = libusb10_do_transfer(devh, endpoint, data, length, transferred,
 	    timeout, LIBUSB_TRANSFER_TYPE_INTERRUPT);
 
-	DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_interrupt_transfer leave");
+	DPRINTF(ctx, LIBUSB_LOG_LEVEL_DEBUG, "libusb_interrupt_transfer leave");
 	return (ret);
 }