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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-12 02:34:40 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-12 02:34:40 +0300 |
commit | 0f4974c439dd7826c85bae4e6a8088ce2db0f498 (patch) | |
tree | fdabc7d9bb7d7bc49aad547c0aac3a633ce01f09 /drivers/char/tty_port.c | |
parent | 3126c136bc30225d7a43af741778aa50e95e467a (diff) | |
parent | 36ba782e9674cdc29ec7003757df0b375e99fa96 (diff) | |
download | linux-0f4974c439dd7826c85bae4e6a8088ce2db0f498.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (58 commits)
tty: split the lock up a bit further
tty: Move the leader test in disassociate
tty: Push the bkl down a bit in the hangup code
tty: Push the lock down further into the ldisc code
tty: push the BKL down into the handlers a bit
tty: moxa: split open lock
tty: moxa: Kill the use of lock_kernel
tty: moxa: Fix modem op locking
tty: moxa: Kill off the throttle method
tty: moxa: Locking clean up
tty: moxa: rework the locking a bit
tty: moxa: Use more tty_port ops
tty: isicom: fix deadlock on shutdown
tty: mxser: Use the new locking rules to fix setserial properly
tty: mxser: use the tty_port_open method
tty: isicom: sort out the board init logic
tty: isicom: switch to the new tty_port_open helper
tty: tty_port: Add a kref object to the tty port
tty: istallion: tty port open/close methods
tty: stallion: Convert to the tty_port_open/close methods
...
Diffstat (limited to 'drivers/char/tty_port.c')
-rw-r--r-- | drivers/char/tty_port.c | 97 |
1 files changed, 79 insertions, 18 deletions
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index c63f3d33914a..be492dd66437 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -25,19 +25,21 @@ void tty_port_init(struct tty_port *port) init_waitqueue_head(&port->close_wait); init_waitqueue_head(&port->delta_msr_wait); mutex_init(&port->mutex); + mutex_init(&port->buf_mutex); spin_lock_init(&port->lock); port->close_delay = (50 * HZ) / 100; port->closing_wait = (3000 * HZ) / 100; + kref_init(&port->kref); } EXPORT_SYMBOL(tty_port_init); int tty_port_alloc_xmit_buf(struct tty_port *port) { /* We may sleep in get_zeroed_page() */ - mutex_lock(&port->mutex); + mutex_lock(&port->buf_mutex); if (port->xmit_buf == NULL) port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); - mutex_unlock(&port->mutex); + mutex_unlock(&port->buf_mutex); if (port->xmit_buf == NULL) return -ENOMEM; return 0; @@ -46,15 +48,32 @@ EXPORT_SYMBOL(tty_port_alloc_xmit_buf); void tty_port_free_xmit_buf(struct tty_port *port) { - mutex_lock(&port->mutex); + mutex_lock(&port->buf_mutex); if (port->xmit_buf != NULL) { free_page((unsigned long)port->xmit_buf); port->xmit_buf = NULL; } - mutex_unlock(&port->mutex); + mutex_unlock(&port->buf_mutex); } EXPORT_SYMBOL(tty_port_free_xmit_buf); +static void tty_port_destructor(struct kref *kref) +{ + struct tty_port *port = container_of(kref, struct tty_port, kref); + if (port->xmit_buf) + free_page((unsigned long)port->xmit_buf); + if (port->ops->destruct) + port->ops->destruct(port); + else + kfree(port); +} + +void tty_port_put(struct tty_port *port) +{ + if (port) + kref_put(&port->kref, tty_port_destructor); +} +EXPORT_SYMBOL(tty_port_put); /** * tty_port_tty_get - get a tty reference @@ -99,10 +118,11 @@ EXPORT_SYMBOL(tty_port_tty_set); static void tty_port_shutdown(struct tty_port *port) { + mutex_lock(&port->mutex); if (port->ops->shutdown && test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) port->ops->shutdown(port); - + mutex_unlock(&port->mutex); } /** @@ -120,8 +140,10 @@ void tty_port_hangup(struct tty_port *port) spin_lock_irqsave(&port->lock, flags); port->count = 0; port->flags &= ~ASYNC_NORMAL_ACTIVE; - if (port->tty) + if (port->tty) { + set_bit(TTY_IO_ERROR, &port->tty->flags); tty_kref_put(port->tty); + } port->tty = NULL; spin_unlock_irqrestore(&port->lock, flags); wake_up_interruptible(&port->open_wait); @@ -198,7 +220,7 @@ EXPORT_SYMBOL(tty_port_lower_dtr_rts); * management of these lines. Note that the dtr/rts raise is done each * iteration as a hangup may have previously dropped them while we wait. */ - + int tty_port_block_til_ready(struct tty_port *port, struct tty_struct *tty, struct file *filp) { @@ -253,7 +275,8 @@ int tty_port_block_til_ready(struct tty_port *port, tty_port_raise_dtr_rts(port); prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); - /* Check for a hangup or uninitialised port. Return accordingly */ + /* Check for a hangup or uninitialised port. + Return accordingly */ if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) { if (port->flags & ASYNC_HUP_NOTIFY) retval = -EAGAIN; @@ -285,11 +308,11 @@ int tty_port_block_til_ready(struct tty_port *port, port->flags |= ASYNC_NORMAL_ACTIVE; spin_unlock_irqrestore(&port->lock, flags); return retval; - } EXPORT_SYMBOL(tty_port_block_til_ready); -int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct file *filp) +int tty_port_close_start(struct tty_port *port, + struct tty_struct *tty, struct file *filp) { unsigned long flags; @@ -299,7 +322,7 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f return 0; } - if( tty->count == 1 && port->count != 1) { + if (tty->count == 1 && port->count != 1) { printk(KERN_WARNING "tty_port_close_start: tty->count = 1 port count = %d.\n", port->count); @@ -331,12 +354,20 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f long timeout; if (bps > 1200) - timeout = max_t(long, (HZ * 10 * port->drain_delay) / bps, - HZ / 10); + timeout = max_t(long, + (HZ * 10 * port->drain_delay) / bps, HZ / 10); else timeout = 2 * HZ; schedule_timeout_interruptible(timeout); } + /* Flush the ldisc buffering */ + tty_ldisc_flush(tty); + + /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to + hang up the line */ + if (tty->termios->c_cflag & HUPCL) + tty_port_lower_dtr_rts(port); + /* 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 */ @@ -348,11 +379,6 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) { unsigned long flags; - tty_ldisc_flush(tty); - - if (tty->termios->c_cflag & HUPCL) - tty_port_lower_dtr_rts(port); - spin_lock_irqsave(&port->lock, flags); tty->closing = 0; @@ -377,7 +403,42 @@ void tty_port_close(struct tty_port *port, struct tty_struct *tty, if (tty_port_close_start(port, tty, filp) == 0) return; tty_port_shutdown(port); + set_bit(TTY_IO_ERROR, &tty->flags); tty_port_close_end(port, tty); tty_port_tty_set(port, NULL); } EXPORT_SYMBOL(tty_port_close); + +int tty_port_open(struct tty_port *port, struct tty_struct *tty, + struct file *filp) +{ + spin_lock_irq(&port->lock); + if (!tty_hung_up_p(filp)) + ++port->count; + spin_unlock_irq(&port->lock); + tty_port_tty_set(port, tty); + + /* + * Do the device-specific open only if the hardware isn't + * already initialized. Serialize open and shutdown using the + * port mutex. + */ + + mutex_lock(&port->mutex); + + if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) { + clear_bit(TTY_IO_ERROR, &tty->flags); + if (port->ops->activate) { + int retval = port->ops->activate(port, tty); + if (retval) { + mutex_unlock(&port->mutex); + return retval; + } + } + set_bit(ASYNCB_INITIALIZED, &port->flags); + } + mutex_unlock(&port->mutex); + return tty_port_block_til_ready(port, tty, filp); +} + +EXPORT_SYMBOL(tty_port_open); |