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tty: Add a full port_close function 

Now we are extracting out methods for shutdown and the like we can add a
proper tty_port_close method that knows all the innards of the tty closing
process and hides the lot from the caller.

At some point in the future this will be paired with a similar open()
helper and the drivers can stick to hardware management.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-09-19 13:13:20 -07:00 committed by Live-CD User
parent 24d481ecae
commit 7ca0ff9ab3
2 changed files with 34 additions and 3 deletions
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29
drivers/char/tty_port.c
View File

@ -96,6 +96,14 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
}
EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port)
{
if (port->ops->shutdown &&
test_and_clear_bit(ASYNC_INITIALIZED, &port->flags))
port->ops->shutdown(port);
}
/**
* tty_port_hangup - hangup helper
* @port: tty port
@ -116,6 +124,7 @@ void tty_port_hangup(struct tty_port *port)
port->tty = NULL;
spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
tty_port_shutdown(port);
}
EXPORT_SYMBOL(tty_port_hangup);
@ -296,15 +305,17 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
if (port->count) {
spin_unlock_irqrestore(&port->lock, flags);
if (port->ops->drop)
port->ops->drop(port);
return 0;
}
port->flags |= ASYNC_CLOSING;
set_bit(ASYNC_CLOSING, &port->flags);
tty->closing = 1;
spin_unlock_irqrestore(&port->lock, flags);
/* Don't block on a stalled port, just pull the chain */
if (tty->flow_stopped)
tty_driver_flush_buffer(tty);
if (port->flags & ASYNC_INITIALIZED &&
if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, port->closing_wait);
if (port->drain_delay) {
@ -318,6 +329,9 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
timeout = 2 * HZ;
schedule_timeout_interruptible(timeout);
}
/* Don't call port->drop for the last reference. Callers will want
to drop the last active reference in ->shutdown() or the tty
shutdown path */
return 1;
}
EXPORT_SYMBOL(tty_port_close_start);
@ -348,3 +362,14 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
spin_unlock_irqrestore(&port->lock, flags);
}
EXPORT_SYMBOL(tty_port_close_end);
void tty_port_close(struct tty_port *port, struct tty_struct *tty,
struct file *filp)
{
if (tty_port_close_start(port, tty, filp) == 0)
return;
tty_port_shutdown(port);
tty_port_close_end(port, tty);
tty_port_tty_set(port, NULL);
}
EXPORT_SYMBOL(tty_port_close);

8
include/linux/tty.h
View File

@ -187,7 +187,12 @@ struct tty_port;
struct tty_port_operations {
/* Return 1 if the carrier is raised */
int (*carrier_raised)(struct tty_port *port);
/* Control the DTR line */
void (*dtr_rts)(struct tty_port *port, int raise);
/* Called when the last close completes or a hangup finishes
IFF the port was initialized. Do not use to free resources */
void (*shutdown)(struct tty_port *port);
void (*drop)(struct tty_port *port);
};
struct tty_port {
@ -459,7 +464,8 @@ extern int tty_port_block_til_ready(struct tty_port *port,
extern int tty_port_close_start(struct tty_port *port,
struct tty_struct *tty, struct file *filp);
extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
extern void tty_port_close(struct tty_port *port,
struct tty_struct *tty, struct file *filp);
extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
extern int tty_unregister_ldisc(int disc);
extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);