tty: Remove chars_in_buffer() line discipline method
The chars_in_buffer() line discipline method serves no functional
purpose, other than as a (dubious) debugging aid for mostly bit-rotting
drivers. Despite being documented as an optional method, every caller
is unconditionally executed (although conditionally compiled).
Furthermore, direct tty->ldisc access without an ldisc ref is unsafe.
Lastly, N_TTY's chars_in_buffer() has warned of removal since 3.12.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 2caaf5a..6ba5681 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -965,8 +965,7 @@
struct serial_state *info = tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
- printk("throttle %s: %d....\n", tty_name(tty),
- tty->ldisc.chars_in_buffer(tty));
+ printk("throttle %s ....\n", tty_name(tty));
#endif
if (serial_paranoia_check(info, tty->name, "rs_throttle"))
@@ -988,8 +987,7 @@
struct serial_state *info = tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
- printk("unthrottle %s: %d....\n", tty_name(tty),
- tty->ldisc.chars_in_buffer(tty));
+ printk("unthrottle %s ....\n", tty_name(tty));
#endif
if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index abbed20..a48e7e6 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -2852,8 +2852,8 @@
unsigned long flags;
#ifdef CY_DEBUG_THROTTLE
- printk(KERN_DEBUG "cyc:throttle %s: %ld...ttyC%d\n", tty_name(tty),
- tty->ldisc.chars_in_buffer(tty), info->line);
+ printk(KERN_DEBUG "cyc:throttle %s ...ttyC%d\n", tty_name(tty),
+ info->line);
#endif
if (serial_paranoia_check(info, tty->name, "cy_throttle"))
@@ -2891,8 +2891,8 @@
unsigned long flags;
#ifdef CY_DEBUG_THROTTLE
- printk(KERN_DEBUG "cyc:unthrottle %s: %ld...ttyC%d\n",
- tty_name(tty), tty_chars_in_buffer(tty), info->line);
+ printk(KERN_DEBUG "cyc:unthrottle %s ...ttyC%d\n",
+ tty_name(tty), info->line);
#endif
if (serial_paranoia_check(info, tty->name, "cy_unthrottle"))
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c3fe026..e3cc277 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2304,21 +2304,6 @@
}
/**
- * gsmld_chars_in_buffer - report available bytes
- * @tty: tty device
- *
- * Report the number of characters buffered to be delivered to user
- * at this instant in time.
- *
- * Locking: gsm lock
- */
-
-static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty)
-{
- return 0;
-}
-
-/**
* gsmld_flush_buffer - clean input queue
* @tty: terminal device
*
@@ -2830,7 +2815,6 @@
.open = gsmld_open,
.close = gsmld_close,
.flush_buffer = gsmld_flush_buffer,
- .chars_in_buffer = gsmld_chars_in_buffer,
.read = gsmld_read,
.write = gsmld_write,
.ioctl = gsmld_ioctl,
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b280abaa..90eca26 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -381,28 +381,6 @@
}
/**
- * n_tty_chars_in_buffer - report available bytes
- * @tty: tty device
- *
- * Report the number of characters buffered to be delivered to user
- * at this instant in time.
- *
- * Locking: exclusive termios_rwsem
- */
-
-static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
-{
- ssize_t n;
-
- WARN_ONCE(1, "%s is deprecated and scheduled for removal.", __func__);
-
- down_write(&tty->termios_rwsem);
- n = chars_in_buffer(tty);
- up_write(&tty->termios_rwsem);
- return n;
-}
-
-/**
* is_utf8_continuation - utf8 multibyte check
* @c: byte to check
*
@@ -2525,7 +2503,6 @@
.open = n_tty_open,
.close = n_tty_close,
.flush_buffer = n_tty_flush_buffer,
- .chars_in_buffer = n_tty_chars_in_buffer,
.read = n_tty_read,
.write = n_tty_write,
.ioctl = n_tty_ioctl,
diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index 802eac7..f624b93 100644
--- a/drivers/tty/rocket.c
+++ b/drivers/tty/rocket.c
@@ -1360,8 +1360,7 @@
struct r_port *info = tty->driver_data;
#ifdef ROCKET_DEBUG_THROTTLE
- printk(KERN_INFO "throttle %s: %d....\n", tty->name,
- tty->ldisc.chars_in_buffer(tty));
+ printk(KERN_INFO "throttle %s ....\n", tty->name);
#endif
if (rocket_paranoia_check(info, "rp_throttle"))
@@ -1377,8 +1376,7 @@
{
struct r_port *info = tty->driver_data;
#ifdef ROCKET_DEBUG_THROTTLE
- printk(KERN_INFO "unthrottle %s: %d....\n", tty->name,
- tty->ldisc.chars_in_buffer(tty));
+ printk(KERN_INFO "unthrottle %s ....\n", tty->name);
#endif
if (rocket_paranoia_check(info, "rp_unthrottle"))
diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c
index f13f2eb..e98aef7 100644
--- a/drivers/tty/serial/crisv10.c
+++ b/drivers/tty/serial/crisv10.c
@@ -2968,7 +2968,7 @@
local_save_flags(flags);
DFLOW(DEBUG_LOG(info->line, "write count %i ", count));
- DFLOW(DEBUG_LOG(info->line, "ldisc %i\n", tty->ldisc.chars_in_buffer(tty)));
+ DFLOW(DEBUG_LOG(info->line, "ldisc\n"));
/* The local_irq_disable/restore_flags pairs below are needed
@@ -3161,10 +3161,9 @@
{
struct e100_serial *info = (struct e100_serial *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
- printk("throttle %s: %lu....\n", tty_name(tty),
- (unsigned long)tty->ldisc.chars_in_buffer(tty));
+ printk("throttle %s ....\n", tty_name(tty));
#endif
- DFLOW(DEBUG_LOG(info->line,"rs_throttle %lu\n", tty->ldisc.chars_in_buffer(tty)));
+ DFLOW(DEBUG_LOG(info->line,"rs_throttle\n"));
/* Do RTS before XOFF since XOFF might take some time */
if (tty->termios.c_cflag & CRTSCTS) {
@@ -3181,10 +3180,9 @@
{
struct e100_serial *info = (struct e100_serial *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
- printk("unthrottle %s: %lu....\n", tty_name(tty),
- (unsigned long)tty->ldisc.chars_in_buffer(tty));
+ printk("unthrottle %s ....\n", tty_name(tty));
#endif
- DFLOW(DEBUG_LOG(info->line,"rs_unthrottle ldisc %d\n", tty->ldisc.chars_in_buffer(tty)));
+ DFLOW(DEBUG_LOG(info->line,"rs_unthrottle ldisc\n"));
DFLOW(DEBUG_LOG(info->line,"rs_unthrottle flip.count: %i\n", tty->flip.count));
/* Do RTS before XOFF since XOFF might take some time */
if (tty->termios.c_cflag & CRTSCTS) {