diff --git a/sys/dev/usb/uvideo.c b/sys/dev/usb/uvideo.c
index 692bf03b36a0..7386ae3e9d4f 100644
--- a/sys/dev/usb/uvideo.c
+++ b/sys/dev/usb/uvideo.c
@@ -787,7 +787,7 @@ uvideo_stream_alloc(void)
 }
 
 
-static usbd_status
+static usbd_status __noinline
 uvideo_init_control(struct uvideo_softc *sc,
 		    const usb_interface_descriptor_t *ifdesc,
 		    usbd_desc_iter_t *iter)
@@ -811,6 +811,7 @@ uvideo_init_control(struct uvideo_softc *sc,
 		if (uvdesc->bDescriptorSubtype < UDESC_INPUT_TERMINAL ||
 		    uvdesc->bDescriptorSubtype > UDESC_EXTENSION_UNIT)
 			continue;
+		KASSERT(nunits < 255);
 		++nunits;
 	}
 
@@ -843,6 +844,7 @@ uvideo_init_control(struct uvideo_softc *sc,
 		/* TODO: free other units before returning? */
 		if (sc->sc_unit[i] == NULL)
 			goto enomem;
+		KASSERT(i < 255);
 		++i;
 	}
 
@@ -875,7 +877,7 @@ uvideo_init_collection(struct uvideo_softc *sc,
  * Allocates space for and initializes a uvideo unit based on the
  * given descriptor.  Returns NULL with bad descriptor or ENOMEM.
  */
-static struct uvideo_unit *
+static struct uvideo_unit * __noinline
 uvideo_unit_alloc(const uvideo_descriptor_t *desc)
 {
 	struct uvideo_unit *vu;
@@ -895,7 +897,7 @@ uvideo_unit_alloc(const uvideo_descriptor_t *desc)
 	return vu;
 }
 
-static usbd_status
+static usbd_status __noinline
 uvideo_unit_init(struct uvideo_unit *vu, const uvideo_descriptor_t *desc)
 {
 	struct uvideo_camera_terminal *ct;
@@ -981,7 +983,7 @@ uvideo_unit_init(struct uvideo_unit *vu, const uvideo_descriptor_t *desc)
 	return USBD_NORMAL_COMPLETION;
 }
 
-static void
+static void __noinline
 uvideo_unit_free(struct uvideo_unit *vu)
 {
 	uvideo_unit_free_sources(vu);
@@ -989,7 +991,7 @@ uvideo_unit_free(struct uvideo_unit *vu)
 	kmem_free(vu, sizeof(*vu));
 }
 
-static usbd_status
+static usbd_status __noinline
 uvideo_unit_alloc_sources(struct uvideo_unit *vu,
 			  uint8_t nsrcs, const uint8_t *src_ids)
 {
@@ -1008,10 +1010,10 @@ uvideo_unit_alloc_sources(struct uvideo_unit *vu,
 	return USBD_NORMAL_COMPLETION;
 }
 
-static void
+static void __noinline
 uvideo_unit_free_sources(struct uvideo_unit *vu)
 {
-	if (vu->vu_nsrcs == 1)
+	if (vu->vu_nsrcs <= 1)
 		return;
 
 	kmem_free(vu->s.vu_src_id_ary,
@@ -1020,7 +1022,7 @@ uvideo_unit_free_sources(struct uvideo_unit *vu)
 	vu->s.vu_src_id_ary = NULL;
 }
 
-static usbd_status
+static usbd_status __noinline
 uvideo_unit_alloc_controls(struct uvideo_unit *vu, uint8_t size,
 			   const uint8_t *controls)
 {
@@ -1034,7 +1036,7 @@ uvideo_unit_alloc_controls(struct uvideo_unit *vu, uint8_t size,
 	return USBD_NORMAL_COMPLETION;
 }
 
-static void
+static void __noinline
 uvideo_unit_free_controls(struct uvideo_unit *vu)
 {
 	kmem_free(vu->vu_controls,