tag	line	file	source code
write_room	2016	drivers/char/console.c	console_driver.write_room = con_write_room;
write_room	2734	drivers/char/cyclades.c	cy_serial_driver.write_room = cy_write_room;
write_room	103	drivers/char/n_tty.c	space = tty->driver.write_room(tty);
write_room	240	drivers/char/pty.c	pty_driver.write_room = pty_write_room;
write_room	2201	drivers/char/scc.c	scc_driver.write_room = scc_write_room;
write_room	2605	drivers/char/serial.c	serial_driver.write_room = rs_write_room;
write_room	130	include/linux/tty_driver.h	int  (*write_room)(struct tty_struct *tty);