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: Jiri 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2021-05-05 11:19:18 +02:00 committed by Greg Kroah-Hartman
parent 9a33fbf9d2
commit fa7501e57e
6 changed files with 0 additions and 55 deletions

View File

@ -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

View File

@ -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)

View File

@ -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,

View File

@ -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,

View File

@ -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,

View File

@ -3270,11 +3270,6 @@ static unsigned int con_write_room(struct tty_struct *tty)
return 32768; /* No limit, really; we're not buffering */
}
static int con_chars_in_buffer(struct tty_struct *tty)
{
return 0; /* we're not buffering */
}
/*
* con_throttle and con_unthrottle are only used for
* paste_selection(), which has to stuff in a large number of
@ -3521,7 +3516,6 @@ static const struct tty_operations con_ops = {
.write_room = con_write_room,
.put_char = con_put_char,
.flush_chars = con_flush_chars,
.chars_in_buffer = con_chars_in_buffer,
.ioctl = vt_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = vt_compat_ioctl,