Commit 76af233d authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

tty: remove unused tty_throttle 



The last user was removed in commit e91e52e4 (n_tty: Fix stuck
throttled driver) in 2013. So remove exported tty_throttle completely.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210510065923.5112-1-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1bf42296

drivers/tty/tty_ioctl.c

+5 −26
Original line number Diff line number Diff line
@@ -96,28 +96,6 @@ void tty_driver_flush_buffer(struct tty_struct *tty) 
}

EXPORT_SYMBOL(tty_driver_flush_buffer);



/**

 *	tty_throttle		-	flow control

 *	@tty: terminal

 *

 *	Indicate that a tty should stop transmitting data down the stack.

 *	Takes the termios rwsem to protect against parallel throttle/unthrottle

 *	and also to ensure the driver can consistently reference its own

 *	termios data at this point when implementing software flow control.

 */



void tty_throttle(struct tty_struct *tty)

{

	down_write(&tty->termios_rwsem);

	/* check TTY_THROTTLED first so it indicates our state */

	if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&

	    tty->ops->throttle)

		tty->ops->throttle(tty);

	tty->flow_change = 0;

	up_write(&tty->termios_rwsem);

}

EXPORT_SYMBOL(tty_throttle);



/**

 *	tty_unthrottle		-	flow control

 *	@tty: terminal
@@ -146,10 +124,11 @@ EXPORT_SYMBOL(tty_unthrottle); 
 *	tty_throttle_safe	-	flow control

 *	@tty: terminal

 *

 *	Similar to tty_throttle() but will only attempt throttle

 *	if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental

 *	throttle due to race conditions when throttling is conditional

 *	on factors evaluated prior to throttling.

 *	Indicate that a tty should stop transmitting data down the stack.

 *	tty_throttle_safe will only attempt throttle if tty->flow_change is

 *	TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race

 *	conditions when throttling is conditional on factors evaluated prior to

 *	throttling.

 *

 *	Returns 0 if tty is throttled (or was already throttled)

 */

include/linux/tty.h

+0 −1
Original line number Diff line number Diff line
@@ -461,7 +461,6 @@ extern int tty_put_char(struct tty_struct *tty, unsigned char c); 
extern unsigned int tty_chars_in_buffer(struct tty_struct *tty);

extern unsigned int tty_write_room(struct tty_struct *tty);

extern void tty_driver_flush_buffer(struct tty_struct *tty);

extern void tty_throttle(struct tty_struct *tty);

extern void tty_unthrottle(struct tty_struct *tty);

extern int tty_throttle_safe(struct tty_struct *tty);

extern int tty_unthrottle_safe(struct tty_struct *tty);

include/linux/tty_driver.h

+1 −1
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ 
 * 	the line discipline are close to full, and it should somehow

 * 	signal that no more characters should be sent to the tty.

 *

 *	Optional: Always invoke via tty_throttle(), called under the

 *	Optional: Always invoke via tty_throttle_safe(), called under the

 *	termios lock.

 * 

 * void (*unthrottle)(struct tty_struct * tty);