tty: rework break handling
Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index ba8782b..a185263 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -218,7 +218,7 @@
config ISI
tristate "Multi-Tech multiport card support (EXPERIMENTAL)"
- depends on SERIAL_NONSTANDARD && PCI
+ depends on SERIAL_NONSTANDARD && PCI && BROKEN
select FW_LOADER
help
This is a driver for the Multi-Tech cards which provide several
diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index 37457e5..3530ff4 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -1248,7 +1248,7 @@
/*
* rs_break() --- routine which turns the break handling on or off
*/
-static void rs_break(struct tty_struct *tty, int break_state)
+static int rs_break(struct tty_struct *tty, int break_state)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
unsigned long flags;
@@ -1263,6 +1263,7 @@
custom.adkcon = AC_UARTBRK;
mb();
local_irq_restore(flags);
+ return 0;
}
diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index e991dc85..fe6d774 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -3700,14 +3700,15 @@
/*
* cy_break() --- routine which turns the break handling on or off
*/
-static void cy_break(struct tty_struct *tty, int break_state)
+static int cy_break(struct tty_struct *tty, int break_state)
{
struct cyclades_port *info = tty->driver_data;
struct cyclades_card *card;
unsigned long flags;
+ int retval = 0;
if (serial_paranoia_check(info, tty->name, "cy_break"))
- return;
+ return -EINVAL;
card = info->card;
@@ -3736,8 +3737,6 @@
}
}
} else {
- int retval;
-
if (break_state == -1) {
retval = cyz_issue_cmd(card,
info->line - card->first_line,
@@ -3758,6 +3757,7 @@
}
}
spin_unlock_irqrestore(&card->card_lock, flags);
+ return retval;
} /* cy_break */
static int get_mon_info(struct cyclades_port *info,
diff --git a/drivers/char/esp.c b/drivers/char/esp.c
index 2eaf09f..7f077c0 100644
--- a/drivers/char/esp.c
+++ b/drivers/char/esp.c
@@ -1725,13 +1725,13 @@
/*
* rs_break() --- routine which turns the break handling on or off
*/
-static void esp_break(struct tty_struct *tty, int break_state)
+static int esp_break(struct tty_struct *tty, int break_state)
{
struct esp_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "esp_break"))
- return;
+ return -EINVAL;
if (break_state == -1) {
spin_lock_irqsave(&info->lock, flags);
@@ -1747,6 +1747,7 @@
serial_out(info, UART_ESI_CMD2, 0x00);
spin_unlock_irqrestore(&info->lock, flags);
}
+ return 0;
}
static int rs_ioctl(struct tty_struct *tty, struct file *file,
diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 7930fba..63d22b5 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -609,7 +609,7 @@
static void stli_stop(struct tty_struct *tty);
static void stli_start(struct tty_struct *tty);
static void stli_flushbuffer(struct tty_struct *tty);
-static void stli_breakctl(struct tty_struct *tty, int state);
+static int stli_breakctl(struct tty_struct *tty, int state);
static void stli_waituntilsent(struct tty_struct *tty, int timeout);
static void stli_sendxchar(struct tty_struct *tty, char ch);
static void stli_hangup(struct tty_struct *tty);
@@ -1909,7 +1909,7 @@
/*****************************************************************************/
-static void stli_breakctl(struct tty_struct *tty, int state)
+static int stli_breakctl(struct tty_struct *tty, int state)
{
struct stlibrd *brdp;
struct stliport *portp;
@@ -1917,15 +1917,16 @@
portp = tty->driver_data;
if (portp == NULL)
- return;
+ return -EINVAL;
if (portp->brdnr >= stli_nrbrds)
- return;
+ return -EINVAL;
brdp = stli_brds[portp->brdnr];
if (brdp == NULL)
- return;
+ return -EINVAL;
arg = (state == -1) ? BREAKON : BREAKOFF;
stli_cmdwait(brdp, portp, A_BREAK, &arg, sizeof(long), 0);
+ return 0;
}
/*****************************************************************************/
diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 2bba250..d3d7864e 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -374,12 +374,13 @@
return ret;
}
-static void moxa_break_ctl(struct tty_struct *tty, int state)
+static int moxa_break_ctl(struct tty_struct *tty, int state)
{
struct moxa_port *port = tty->driver_data;
moxafunc(port->tableAddr, state ? FC_SendBreak : FC_StopBreak,
Magic_code);
+ return 0;
}
static const struct tty_operations moxa_ops = {
diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 1fb2557..f04c3c5 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -2183,7 +2183,7 @@
/*
* mxser_rs_break() --- routine which turns the break handling on or off
*/
-static void mxser_rs_break(struct tty_struct *tty, int break_state)
+static int mxser_rs_break(struct tty_struct *tty, int break_state)
{
struct mxser_port *info = tty->driver_data;
unsigned long flags;
@@ -2196,6 +2196,7 @@
outb(inb(info->ioaddr + UART_LCR) & ~UART_LCR_SBC,
info->ioaddr + UART_LCR);
spin_unlock_irqrestore(&info->slock, flags);
+ return 0;
}
static void mxser_receive_chars(struct mxser_port *port, int *status)
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index b694d43..d1fceab 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -2230,7 +2230,7 @@
* Arguments: tty pointer to tty instance data
* break_state -1=set break condition, 0=clear
*/
-static void mgslpc_break(struct tty_struct *tty, int break_state)
+static int mgslpc_break(struct tty_struct *tty, int break_state)
{
MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
unsigned long flags;
@@ -2240,7 +2240,7 @@
__FILE__,__LINE__, info->device_name, break_state);
if (mgslpc_paranoia_check(info, tty->name, "mgslpc_break"))
- return;
+ return -EINVAL;
spin_lock_irqsave(&info->lock,flags);
if (break_state == -1)
@@ -2248,6 +2248,7 @@
else
clear_reg_bits(info, CHA+DAFO, BIT6);
spin_unlock_irqrestore(&info->lock,flags);
+ return 0;
}
/* Service an IOCTL request
diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index e670eae..584d791 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -1236,13 +1236,13 @@
}
}
-static void rp_break(struct tty_struct *tty, int break_state)
+static int rp_break(struct tty_struct *tty, int break_state)
{
struct r_port *info = (struct r_port *) tty->driver_data;
unsigned long flags;
if (rocket_paranoia_check(info, "rp_break"))
- return;
+ return -EINVAL;
spin_lock_irqsave(&info->slock, flags);
if (break_state == -1)
@@ -1250,6 +1250,7 @@
else
sClrBreak(&info->channel);
spin_unlock_irqrestore(&info->slock, flags);
+ return 0;
}
/*
diff --git a/drivers/char/sx.c b/drivers/char/sx.c
index d5cffcd..2162439b 100644
--- a/drivers/char/sx.c
+++ b/drivers/char/sx.c
@@ -1840,7 +1840,7 @@
return rc;
}
-static void sx_break(struct tty_struct *tty, int flag)
+static int sx_break(struct tty_struct *tty, int flag)
{
struct sx_port *port = tty->driver_data;
int rv;
@@ -1857,6 +1857,7 @@
read_sx_byte(port->board, CHAN_OFFSET(port, hi_hstat)));
unlock_kernel();
func_exit();
+ return 0;
}
static int sx_tiocmget(struct tty_struct *tty, struct file *file)
diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index 527d220..ef6706f 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -2897,9 +2897,9 @@
*
* Arguments: tty pointer to tty instance data
* break_state -1=set break condition, 0=clear
- * Return Value: None
+ * Return Value: error code
*/
-static void mgsl_break(struct tty_struct *tty, int break_state)
+static int mgsl_break(struct tty_struct *tty, int break_state)
{
struct mgsl_struct * info = (struct mgsl_struct *)tty->driver_data;
unsigned long flags;
@@ -2909,7 +2909,7 @@
__FILE__,__LINE__, info->device_name, break_state);
if (mgsl_paranoia_check(info, tty->name, "mgsl_break"))
- return;
+ return -EINVAL;
spin_lock_irqsave(&info->irq_spinlock,flags);
if (break_state == -1)
@@ -2917,6 +2917,7 @@
else
usc_OutReg(info,IOCR,(u16)(usc_InReg(info,IOCR) & ~BIT7));
spin_unlock_irqrestore(&info->irq_spinlock,flags);
+ return 0;
} /* end of mgsl_break() */
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 2c3e43b..cf87bb8 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -165,7 +165,7 @@
static int chars_in_buffer(struct tty_struct *tty);
static void throttle(struct tty_struct * tty);
static void unthrottle(struct tty_struct * tty);
-static void set_break(struct tty_struct *tty, int break_state);
+static int set_break(struct tty_struct *tty, int break_state);
/*
* generic HDLC support and callbacks
@@ -513,7 +513,7 @@
static int tiocmget(struct tty_struct *tty, struct file *file);
static int tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
-static void set_break(struct tty_struct *tty, int break_state);
+static int set_break(struct tty_struct *tty, int break_state);
static int get_interface(struct slgt_info *info, int __user *if_mode);
static int set_interface(struct slgt_info *info, int if_mode);
static int set_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
@@ -1452,14 +1452,14 @@
* set or clear transmit break condition
* break_state -1=set break condition, 0=clear
*/
-static void set_break(struct tty_struct *tty, int break_state)
+static int set_break(struct tty_struct *tty, int break_state)
{
struct slgt_info *info = tty->driver_data;
unsigned short value;
unsigned long flags;
if (sanity_check(info, tty->name, "set_break"))
- return;
+ return -EINVAL;
DBGINFO(("%s set_break(%d)\n", info->device_name, break_state));
spin_lock_irqsave(&info->lock,flags);
@@ -1470,6 +1470,7 @@
value &= ~BIT6;
wr_reg16(info, TCR, value);
spin_unlock_irqrestore(&info->lock,flags);
+ return 0;
}
#if SYNCLINK_GENERIC_HDLC
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index 5768c41..c0490cb 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -527,7 +527,7 @@
static int chars_in_buffer(struct tty_struct *tty);
static void throttle(struct tty_struct * tty);
static void unthrottle(struct tty_struct * tty);
-static void set_break(struct tty_struct *tty, int break_state);
+static int set_break(struct tty_struct *tty, int break_state);
#if SYNCLINK_GENERIC_HDLC
#define dev_to_port(D) (dev_to_hdlc(D)->priv)
@@ -552,7 +552,7 @@
static int tiocmget(struct tty_struct *tty, struct file *file);
static int tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
-static void set_break(struct tty_struct *tty, int break_state);
+static int set_break(struct tty_struct *tty, int break_state);
static void add_device(SLMP_INFO *info);
static void device_init(int adapter_num, struct pci_dev *pdev);
@@ -1587,7 +1587,7 @@
/* set or clear transmit break condition
* break_state -1=set break condition, 0=clear
*/
-static void set_break(struct tty_struct *tty, int break_state)
+static int set_break(struct tty_struct *tty, int break_state)
{
unsigned char RegValue;
SLMP_INFO * info = (SLMP_INFO *)tty->driver_data;
@@ -1598,7 +1598,7 @@
__FILE__,__LINE__, info->device_name, break_state);
if (sanity_check(info, tty->name, "set_break"))
- return;
+ return -EINVAL;
spin_lock_irqsave(&info->lock,flags);
RegValue = read_reg(info, CTL);
@@ -1608,6 +1608,7 @@
RegValue &= ~BIT3;
write_reg(info, CTL, RegValue);
spin_unlock_irqrestore(&info->lock,flags);
+ return 0;
}
#if SYNCLINK_GENERIC_HDLC
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index d27a08b..d94cd84 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2849,16 +2849,29 @@
static int send_break(struct tty_struct *tty, unsigned int duration)
{
- if (tty_write_lock(tty, 0) < 0)
- return -EINTR;
- tty->ops->break_ctl(tty, -1);
- if (!signal_pending(current))
- msleep_interruptible(duration);
- tty->ops->break_ctl(tty, 0);
- tty_write_unlock(tty);
- if (signal_pending(current))
- return -EINTR;
- return 0;
+ int retval;
+
+ if (tty->ops->break_ctl == NULL)
+ return 0;
+
+ if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
+ retval = tty->ops->break_ctl(tty, duration);
+ else {
+ /* Do the work ourselves */
+ if (tty_write_lock(tty, 0) < 0)
+ return -EINTR;
+ retval = tty->ops->break_ctl(tty, -1);
+ if (retval)
+ goto out;
+ if (!signal_pending(current))
+ msleep_interruptible(duration);
+ retval = tty->ops->break_ctl(tty, 0);
+out:
+ tty_write_unlock(tty);
+ if (signal_pending(current))
+ retval = -EINTR;
+ }
+ return retval;
}
/**
@@ -2949,36 +2962,6 @@
tty->driver->subtype == PTY_TYPE_MASTER)
real_tty = tty->link;
- /*
- * Break handling by driver
- */
-
- retval = -EINVAL;
-
- if (!tty->ops->break_ctl) {
- switch (cmd) {
- case TIOCSBRK:
- case TIOCCBRK:
- if (tty->ops->ioctl)
- retval = tty->ops->ioctl(tty, file, cmd, arg);
- if (retval != -EINVAL && retval != -ENOIOCTLCMD)
- printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
- return retval;
-
- /* These two ioctl's always return success; even if */
- /* the driver doesn't support them. */
- case TCSBRK:
- case TCSBRKP:
- if (!tty->ops->ioctl)
- return 0;
- retval = tty->ops->ioctl(tty, file, cmd, arg);
- if (retval != -EINVAL && retval != -ENOIOCTLCMD)
- printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
- if (retval == -ENOIOCTLCMD)
- retval = 0;
- return retval;
- }
- }
/*
* Factor out some common prep work
@@ -3000,6 +2983,9 @@
break;
}
+ /*
+ * Now do the stuff.
+ */
switch (cmd) {
case TIOCSTI:
return tiocsti(tty, p);
@@ -3043,12 +3029,11 @@
*/
case TIOCSBRK: /* Turn break on, unconditionally */
if (tty->ops->break_ctl)
- tty->ops->break_ctl(tty, -1);
+ return tty->ops->break_ctl(tty, -1);
return 0;
-
case TIOCCBRK: /* Turn break off, unconditionally */
if (tty->ops->break_ctl)
- tty->ops->break_ctl(tty, 0);
+ return tty->ops->break_ctl(tty, 0);
return 0;
case TCSBRK: /* SVID version: non-zero arg --> no break */
/* non-zero arg means wait for all output data
diff --git a/drivers/char/vme_scc.c b/drivers/char/vme_scc.c
index f17ac04..69c5afe 100644
--- a/drivers/char/vme_scc.c
+++ b/drivers/char/vme_scc.c
@@ -85,7 +85,7 @@
static irqreturn_t scc_stat_int(int irq, void *data);
static irqreturn_t scc_spcond_int(int irq, void *data);
static void scc_setsignals(struct scc_port *port, int dtr, int rts);
-static void scc_break_ctl(struct tty_struct *tty, int break_state);
+static int scc_break_ctl(struct tty_struct *tty, int break_state);
static struct tty_driver *scc_driver;
@@ -942,7 +942,7 @@
}
-static void scc_break_ctl(struct tty_struct *tty, int break_state)
+static int scc_break_ctl(struct tty_struct *tty, int break_state)
{
struct scc_port *port = (struct scc_port *)tty->driver_data;
unsigned long flags;
@@ -952,6 +952,7 @@
SCCmod(TX_CTRL_REG, ~TCR_SEND_BREAK,
break_state ? TCR_SEND_BREAK : 0);
local_irq_restore(flags);
+ return 0;
}
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 8a35029..19e005e 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1302,11 +1302,12 @@
#endif
}
-static void capinc_tty_break_ctl(struct tty_struct *tty, int state)
+static int capinc_tty_break_ctl(struct tty_struct *tty, int state)
{
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_break_ctl(%d)\n", state);
#endif
+ return 0;
}
static void capinc_tty_flush_buffer(struct tty_struct *tty)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0bce1fe..f977c98 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -934,7 +934,7 @@
return ret;
}
-static void uart_break_ctl(struct tty_struct *tty, int break_state)
+static int uart_break_ctl(struct tty_struct *tty, int break_state)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->port;
@@ -945,6 +945,7 @@
port->ops->break_ctl(port, break_state);
mutex_unlock(&state->mutex);
+ return 0;
}
static int uart_do_autoconfig(struct uart_state *state)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 95ae637..0725b18 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -732,13 +732,16 @@
tasklet_schedule(&acm->urb_task);
}
-static void acm_tty_break_ctl(struct tty_struct *tty, int state)
+static int acm_tty_break_ctl(struct tty_struct *tty, int state)
{
struct acm *acm = tty->driver_data;
+ int retval;
if (!ACM_READY(acm))
- return;
- if (acm_send_break(acm, state ? 0xffff : 0))
+ return -EINVAL;
+ retval = acm_send_break(acm, state ? 0xffff : 0);
+ if (retval < 0)
dbg("send break failed");
+ return retval;
}
static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 51917b0..8c2d531 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -395,7 +395,7 @@
tty_termios_copy_hw(tty->termios, old);
}
-static void serial_break(struct tty_struct *tty, int break_state)
+static int serial_break(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
@@ -409,6 +409,7 @@
port->serial->type->break_ctl(tty, break_state);
unlock_kernel();
}
+ return 0;
}
static int serial_read_proc(char *page, char **start, off_t off, int count,
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index d2a0035..e1065ac 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -135,7 +135,7 @@
*
* Optional:
*
- * void (*break_ctl)(struct tty_stuct *tty, int state);
+ * int (*break_ctl)(struct tty_stuct *tty, int state);
*
* This optional routine requests the tty driver to turn on or
* off BREAK status on the RS-232 port. If state is -1,
@@ -146,6 +146,10 @@
* handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
* TIOCCBRK.
*
+ * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
+ * will also be called with actual times and the hardware is expected
+ * to do the delay work itself. 0 and -1 are still used for on/off.
+ *
* Optional: Required for TCSBRK/BRKP/etc handling.
*
* void (*wait_until_sent)(struct tty_struct *tty, int timeout);
@@ -192,7 +196,7 @@
void (*stop)(struct tty_struct *tty);
void (*start)(struct tty_struct *tty);
void (*hangup)(struct tty_struct *tty);
- void (*break_ctl)(struct tty_struct *tty, int state);
+ int (*break_ctl)(struct tty_struct *tty, int state);
void (*flush_buffer)(struct tty_struct *tty);
void (*set_ldisc)(struct tty_struct *tty);
void (*wait_until_sent)(struct tty_struct *tty, int timeout);
@@ -285,12 +289,18 @@
* TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
* use dynamic memory keyed through the devpts filesystem. This
* is only applicable to the pty driver.
+ *
+ * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
+ * the requested timeout to the caller instead of using a simple
+ * on/off interface.
+ *
*/
#define TTY_DRIVER_INSTALLED 0x0001
#define TTY_DRIVER_RESET_TERMIOS 0x0002
#define TTY_DRIVER_REAL_RAW 0x0004
#define TTY_DRIVER_DYNAMIC_DEV 0x0008
#define TTY_DRIVER_DEVPTS_MEM 0x0010
+#define TTY_DRIVER_HARDWARE_BREAK 0x0020
/* tty driver types */
#define TTY_DRIVER_TYPE_SYSTEM 0x0001