... and size_t is unsigned.
Index: sys/dev/wscons/wsmouse.c =================================================================== RCS file: /home/OpenBSD/cvs/src/sys/dev/wscons/wsmouse.c,v retrieving revision 1.31 diff -u -p -U8 -r1.31 wsmouse.c --- sys/dev/wscons/wsmouse.c 5 Jul 2016 19:33:14 -0000 1.31 +++ sys/dev/wscons/wsmouse.c 12 Jul 2016 15:12:15 -0000 @@ -1319,17 +1319,17 @@ wsmouse_init_scaling(struct wsmouseinput void wsmouse_set_param(struct device *sc, size_t param, int value) { struct wsmouseinput *input = &((struct wsmouse_softc *) sc)->input; struct wsmouseparams *params = &input->params; int *p; - if (param < 0 || param > WSMPARAM_LASTFIELD) { + if (param > WSMPARAM_LASTFIELD) { printf("wsmouse_set_param: invalid parameter type\n"); return; } p = (int *) (((void *) params) + param); *p = value; if (IS_WSMFLTR_PARAM(param)) {