extern int sysctl_fast_poll_increase;
extern char sysctl_devname[];
extern int sysctl_max_baud_rate;
-extern int sysctl_min_tx_turn_time;
-extern int sysctl_max_tx_data_size;
-extern int sysctl_max_tx_window;
+extern unsigned int sysctl_min_tx_turn_time;
+extern unsigned int sysctl_max_tx_data_size;
+extern unsigned int sysctl_max_tx_window;
extern int sysctl_max_noreply_time;
extern int sysctl_warn_noreply_time;
extern int sysctl_lap_keepalive_time;