From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
linux-kernel@vger.kernel.org,
Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH v3 05/19] tty: Remove chars_in_buffer() line discipline method
Date: Sun, 10 Jan 2016 22:40:54 -0800 [thread overview]
Message-ID: <1452494468-21359-6-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1452494468-21359-1-git-send-email-peter@hurleysoftware.com>
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>
---
Documentation/serial/tty.txt | 3 ---
drivers/tty/amiserial.c | 6 ++----
drivers/tty/cyclades.c | 8 ++++----
drivers/tty/n_gsm.c | 16 ----------------
drivers/tty/n_tty.c | 23 -----------------------
drivers/tty/rocket.c | 6 ++----
drivers/tty/serial/crisv10.c | 12 +++++-------
include/linux/tty_ldisc.h | 7 -------
8 files changed, 13 insertions(+), 68 deletions(-)
diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt
index bc3842d..798cba8 100644
--- a/Documentation/serial/tty.txt
+++ b/Documentation/serial/tty.txt
@@ -72,9 +72,6 @@ flush_buffer() - (optional) May be called at any point between
open and close, and instructs the line discipline
to empty its input buffer.
-chars_in_buffer() - (optional) Report the number of bytes in the input
- buffer.
-
set_termios() - (optional) Called on termios structure changes.
The caller passes the old termios data and the
current data is in the tty. Called under the
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 @@ static void rs_throttle(struct tty_struct * tty)
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 @@ static void rs_unthrottle(struct tty_struct * tty)
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 @@ static void cy_throttle(struct tty_struct *tty)
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 @@ static void cy_unthrottle(struct tty_struct *tty)
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 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
}
/**
- * 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 @@ static struct tty_ldisc_ops tty_ldisc_packet = {
.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 d9a5fc2..e09fd58 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -384,28 +384,6 @@ static void n_tty_flush_buffer(struct tty_struct *tty)
}
/**
- * 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
*
@@ -2528,7 +2506,6 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
.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 @@ static void rp_throttle(struct tty_struct *tty)
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 @@ static void rp_unthrottle(struct tty_struct *tty)
{
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 @@ static int rs_raw_write(struct tty_struct *tty,
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 @@ rs_throttle(struct tty_struct * tty)
{
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 @@ rs_unthrottle(struct tty_struct * tty)
{
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) {
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 00c9d68..6101ab8 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -25,12 +25,6 @@
* buffers of any input characters it may have queued to be
* delivered to the user mode process.
*
- * ssize_t (*chars_in_buffer)(struct tty_struct *tty);
- *
- * This function returns the number of input characters the line
- * discipline may have queued up to be delivered to the user mode
- * process.
- *
* ssize_t (*read)(struct tty_struct * tty, struct file * file,
* unsigned char * buf, size_t nr);
*
@@ -188,7 +182,6 @@ struct tty_ldisc_ops {
int (*open)(struct tty_struct *);
void (*close)(struct tty_struct *);
void (*flush_buffer)(struct tty_struct *tty);
- ssize_t (*chars_in_buffer)(struct tty_struct *tty);
ssize_t (*read)(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr);
ssize_t (*write)(struct tty_struct *tty, struct file *file,
--
2.7.0
next prev parent reply other threads:[~2016-01-11 6:45 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-27 21:38 [PATCH 00/19] Fix driver crashes on hangup Peter Hurley
2015-11-27 21:38 ` [PATCH 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2015-11-27 21:38 ` [PATCH 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2015-11-27 21:39 ` [PATCH 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2015-12-02 7:47 ` Marcel Holtmann
2015-11-27 21:39 ` [PATCH 04/19] NFC: nci: " Peter Hurley
2015-11-27 21:39 ` [PATCH 05/19] tty: Remove chars_in_buffer() line discipline method Peter Hurley
2015-11-27 21:39 ` [PATCH 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2015-11-27 21:39 ` [PATCH 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2015-11-27 21:39 ` [PATCH 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2015-11-27 21:39 ` [PATCH 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2015-11-27 21:39 ` [PATCH 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2015-11-27 21:39 ` [PATCH 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2015-11-27 21:39 ` [PATCH 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2015-11-27 21:39 ` [PATCH 13/19] tty: Handle NULL tty->ldisc Peter Hurley
2015-11-27 21:39 ` [PATCH 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2015-11-27 21:39 ` [PATCH 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2015-11-27 21:39 ` [PATCH 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2015-11-27 21:39 ` [PATCH 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2015-11-27 21:39 ` [PATCH 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2015-11-27 21:39 ` [PATCH 19/19] tty: Touch up style issues in ldisc core Peter Hurley
2016-01-10 4:40 ` [PATCH v2 00/19] Fix driver crashes on hangup Peter Hurley
2016-01-10 4:40 ` [PATCH v2 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2016-01-10 4:40 ` [PATCH v2 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2016-01-10 4:40 ` [PATCH v2 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2016-01-10 4:40 ` [PATCH v2 04/19] NFC: nci: " Peter Hurley
2016-01-10 4:40 ` [PATCH v2 05/19] tty: Remove chars_in_buffer() line discipline method Peter Hurley
2016-01-10 4:40 ` [PATCH v2 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2016-01-10 5:24 ` Peter Hurley
2016-01-10 4:40 ` [PATCH v2 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2016-01-10 5:26 ` Peter Hurley
2016-01-10 4:40 ` [PATCH v2 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2016-01-10 4:41 ` [PATCH v2 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2016-01-10 23:16 ` Ben Hutchings
2016-01-11 0:25 ` Peter Hurley
2016-01-11 5:40 ` Peter Hurley
2016-01-11 10:37 ` Ben Hutchings
2016-01-10 4:41 ` [PATCH v2 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2016-01-10 4:41 ` [PATCH v2 13/19] tty: Handle NULL tty->ldisc Peter Hurley
2016-01-10 4:41 ` [PATCH v2 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2016-01-10 4:41 ` [PATCH v2 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2016-01-10 4:41 ` [PATCH v2 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2016-01-10 4:41 ` [PATCH v2 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2016-01-10 6:24 ` kbuild test robot
2016-01-10 6:24 ` [PATCH] tty: fix badzero.cocci warnings kbuild test robot
2016-01-10 7:02 ` Peter Hurley
2016-01-10 4:41 ` [PATCH v2 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2016-01-10 4:41 ` [PATCH v2 19/19] tty: Avoid unnecessary temporaries for tty->ldisc Peter Hurley
2016-01-11 6:40 ` [PATCH v3 00/19] Fix driver crashes on hangup Peter Hurley
2016-01-11 6:40 ` [PATCH v3 01/19] staging: digi: Replace open-coded tty_wakeup() Peter Hurley
2016-01-11 6:40 ` [PATCH v3 02/19] serial: 68328: Remove bogus ldisc reset Peter Hurley
2016-01-11 14:12 ` One Thousand Gnomes
2016-01-11 6:40 ` [PATCH v3 03/19] bluetooth: hci_ldisc: Remove dead code Peter Hurley
2016-01-11 6:40 ` [PATCH v3 04/19] NFC: nci: " Peter Hurley
2016-01-11 6:40 ` Peter Hurley [this message]
2016-01-11 6:40 ` [PATCH v3 06/19] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Peter Hurley
2016-01-11 6:40 ` [PATCH v3 07/19] n_tty: Fix unsafe reference to "other" ldisc Peter Hurley
2016-01-11 6:40 ` [PATCH v3 08/19] tty: Reset c_line from driver's init_termios Peter Hurley
2016-01-11 6:40 ` [PATCH v3 09/19] staging/speakup: Use tty_ldisc_ref() for paste kworker Peter Hurley
2016-01-11 6:40 ` [PATCH v3 10/19] tty: Fix comments for tty_ldisc_get() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 11/19] tty: Fix comments for tty_ldisc_release() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 12/19] tty: Prepare for destroying line discipline on hangup Peter Hurley
2016-01-11 6:41 ` [PATCH v3 13/19] tty: Handle NULL tty->ldisc Peter Hurley
2016-01-11 6:41 ` [PATCH v3 14/19] tty: Move tty_ldisc_kill() Peter Hurley
2016-01-11 6:41 ` [PATCH v3 15/19] tty: Use 'disc' for line discipline index name Peter Hurley
2016-01-11 6:41 ` [PATCH v3 16/19] tty: Refactor tty_ldisc_reinit() for reuse Peter Hurley
2016-01-11 6:41 ` [PATCH v3 17/19] tty: Destroy ldisc instance on hangup Peter Hurley
2016-01-11 6:41 ` [PATCH v3 18/19] tty: Document c_line == N_TTY initial condition Peter Hurley
2016-01-11 6:41 ` [PATCH v3 19/19] tty: Avoid unnecessary temporaries for tty->ldisc Peter Hurley
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