Commit fa7501e5 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

tty: remove tty_operations::chars_in_buffer for non-buffering 



The only user of tty_ops::chars_in_buffer is tty_chars_in_buffer. And it
considers tty_ops::chars_in_buffer optional. In case it's NULL, zero is
returned. So remove all those chars_in_buffer from tty_ops which return
zero. (Zero means such driver doesn't buffer.)

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210505091928.22010-26-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9a33fbf9

arch/alpha/kernel/srmcons.c

+0 −7
Original line number Diff line number Diff line
@@ -148,12 +148,6 @@ srmcons_write_room(struct tty_struct *tty) 
	return 512;

}



static int

srmcons_chars_in_buffer(struct tty_struct *tty)

{

	return 0;

}



static int

srmcons_open(struct tty_struct *tty, struct file *filp)

{
@@ -200,7 +194,6 @@ static const struct tty_operations srmcons_ops = { 
	.close		= srmcons_close,

	.write		= srmcons_write,

	.write_room	= srmcons_write_room,

	.chars_in_buffer= srmcons_chars_in_buffer,

};



static int __init

arch/parisc/kernel/pdc_cons.c

+0 −6
Original line number Diff line number Diff line
@@ -108,17 +108,11 @@ static unsigned int pdc_console_tty_write_room(struct tty_struct *tty) 
	return 32768; /* no limit, no buffer used */

}



static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)

{

	return 0; /* no buffer */

}



static const struct tty_operations pdc_console_tty_ops = {

	.open = pdc_console_tty_open,

	.close = pdc_console_tty_close,

	.write = pdc_console_tty_write,

	.write_room = pdc_console_tty_write_room,

	.chars_in_buffer = pdc_console_tty_chars_in_buffer,

};



static void pdc_console_poll(struct timer_list *unused)

arch/xtensa/platforms/iss/console.c

+0 −7
Original line number Diff line number Diff line
@@ -106,12 +106,6 @@ static unsigned int rs_write_room(struct tty_struct *tty) 
	return 2 * 1024;

}



static int rs_chars_in_buffer(struct tty_struct *tty)

{

	/* the iss doesn't buffer characters */

	return 0;

}



static void rs_hangup(struct tty_struct *tty)

{

	/* Stub, once again.. */
@@ -135,7 +129,6 @@ static const struct tty_operations serial_ops = { 
	.put_char = rs_put_char,

	.flush_chars = rs_flush_chars,

	.write_room = rs_write_room,

	.chars_in_buffer = rs_chars_in_buffer,

	.hangup = rs_hangup,

	.wait_until_sent = rs_wait_until_sent,

	.proc_show = rs_proc_show,

drivers/s390/char/tty3270.c

+0 −12
Original line number Diff line number Diff line
@@ -1756,17 +1756,6 @@ tty3270_flush_chars(struct tty_struct *tty) 
	}

}



/*

 * Returns the number of characters in the output buffer. This is

 * used in tty_wait_until_sent to wait until all characters have

 * appeared on the screen.

 */

static int

tty3270_chars_in_buffer(struct tty_struct *tty)

{

	return 0;

}



static void

tty3270_flush_buffer(struct tty_struct *tty)

{
@@ -1892,7 +1881,6 @@ static const struct tty_operations tty3270_ops = { 
	.put_char = tty3270_put_char,

	.flush_chars = tty3270_flush_chars,

	.write_room = tty3270_write_room,

	.chars_in_buffer = tty3270_chars_in_buffer,

	.flush_buffer = tty3270_flush_buffer,

	.throttle = tty3270_throttle,

	.unthrottle = tty3270_unthrottle,

drivers/tty/pty.c

+0 −17
Original line number Diff line number Diff line
@@ -143,19 +143,6 @@ static unsigned int pty_write_room(struct tty_struct *tty) 
	return tty_buffer_space_avail(tty->link->port);

}



/**

 *	pty_chars_in_buffer	-	characters currently in our tx queue

 *	@tty: our tty

 *

 *	Report how much we have in the transmit queue. As everything is

 *	instantly at the other end this is easy to implement.

 */



static int pty_chars_in_buffer(struct tty_struct *tty)

{

	return 0;

}



/* Set the lock flag on a pty */

static int pty_set_lock(struct tty_struct *tty, int __user *arg)

{
@@ -525,7 +512,6 @@ static const struct tty_operations master_pty_ops_bsd = { 
	.write = pty_write,

	.write_room = pty_write_room,

	.flush_buffer = pty_flush_buffer,

	.chars_in_buffer = pty_chars_in_buffer,

	.unthrottle = pty_unthrottle,

	.ioctl = pty_bsd_ioctl,

	.compat_ioctl = pty_bsd_compat_ioctl,
@@ -541,7 +527,6 @@ static const struct tty_operations slave_pty_ops_bsd = { 
	.write = pty_write,

	.write_room = pty_write_room,

	.flush_buffer = pty_flush_buffer,

	.chars_in_buffer = pty_chars_in_buffer,

	.unthrottle = pty_unthrottle,

	.set_termios = pty_set_termios,

	.cleanup = pty_cleanup,
@@ -776,7 +761,6 @@ static const struct tty_operations ptm_unix98_ops = { 
	.write = pty_write,

	.write_room = pty_write_room,

	.flush_buffer = pty_flush_buffer,

	.chars_in_buffer = pty_chars_in_buffer,

	.unthrottle = pty_unthrottle,

	.ioctl = pty_unix98_ioctl,

	.compat_ioctl = pty_unix98_compat_ioctl,
@@ -794,7 +778,6 @@ static const struct tty_operations pty_unix98_ops = { 
	.write = pty_write,

	.write_room = pty_write_room,

	.flush_buffer = pty_flush_buffer,

	.chars_in_buffer = pty_chars_in_buffer,

	.unthrottle = pty_unthrottle,

	.set_termios = pty_set_termios,

	.start = pty_start,