From 3e61696bdc2103107674b06d0daf30b76193e922 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 2 Jan 2009 13:45:26 +0000 Subject: [PATCH] isicom: redo locking to use tty port locks This helps set the basis for moving block_til_ready into common code. We also introduce a tty_port_hangup helper as this will also be generally needed. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/isicom.c | 35 +++++++++++++++-------------------- drivers/char/synclinkmp.c | 20 ++++++++++++++------ drivers/char/tty_port.c | 24 ++++++++++++++++++++++++ include/linux/tty.h | 1 + 4 files changed, 54 insertions(+), 26 deletions(-) diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c index a449449e301..db53db91ae4 100644 --- a/drivers/char/isicom.c +++ b/drivers/char/isicom.c @@ -841,7 +841,6 @@ static int isicom_carrier_raised(struct tty_port *port) static int block_til_ready(struct tty_struct *tty, struct file *filp, struct isi_port *ip) { - struct isi_board *card = ip->card; struct tty_port *port = &ip->port; int do_clocal = 0, retval; unsigned long flags; @@ -876,11 +875,11 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, retval = 0; add_wait_queue(&port->open_wait, &wait); - spin_lock_irqsave(&card->card_lock, flags); + spin_lock_irqsave(&port->lock, flags); if (!tty_hung_up_p(filp)) port->count--; port->blocked_open++; - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->lock, flags); while (1) { tty_port_raise_dtr_rts(port); @@ -905,14 +904,13 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, } set_current_state(TASK_RUNNING); remove_wait_queue(&port->open_wait, &wait); - spin_lock_irqsave(&card->card_lock, flags); + spin_lock_irqsave(&port->lock, flags); if (!tty_hung_up_p(filp)) port->count++; port->blocked_open--; - spin_unlock_irqrestore(&card->card_lock, flags); - if (retval) - return retval; - port->flags |= ASYNC_NORMAL_ACTIVE; + if (retval == 0) + port->flags |= ASYNC_NORMAL_ACTIVE; + spin_unlock_irqrestore(&port->lock, flags); return 0; } @@ -1034,9 +1032,9 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) pr_dbg("Close start!!!.\n"); - spin_lock_irqsave(&card->card_lock, flags); + spin_lock_irqsave(&port->port.lock, flags); if (tty_hung_up_p(filp)) { - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->port.lock, flags); return; } @@ -1054,12 +1052,12 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) } if (port->port.count) { - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->port.lock, flags); return; } port->port.flags |= ASYNC_CLOSING; tty->closing = 1; - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->port.lock, flags); if (port->port.closing_wait != ASYNC_CLOSING_WAIT_NONE) tty_wait_until_sent(tty, port->port.closing_wait); @@ -1076,22 +1074,22 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) isicom_flush_buffer(tty); tty_ldisc_flush(tty); - spin_lock_irqsave(&card->card_lock, flags); + spin_lock_irqsave(&port->port.lock, flags); tty->closing = 0; if (port->port.blocked_open) { - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->port.lock, flags); if (port->port.close_delay) { pr_dbg("scheduling until time out.\n"); msleep_interruptible( jiffies_to_msecs(port->port.close_delay)); } - spin_lock_irqsave(&card->card_lock, flags); + spin_lock_irqsave(&port->port.lock, flags); wake_up_interruptible(&port->port.open_wait); } port->port.flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING); wake_up_interruptible(&port->port.close_wait); - spin_unlock_irqrestore(&card->card_lock, flags); + spin_unlock_irqrestore(&port->port.lock, flags); } /* write et all */ @@ -1430,10 +1428,7 @@ static void isicom_hangup(struct tty_struct *tty) isicom_shutdown_port(port); spin_unlock_irqrestore(&port->card->card_lock, flags); - port->port.count = 0; - port->port.flags &= ~ASYNC_NORMAL_ACTIVE; - tty_port_tty_set(&port->port, NULL); - wake_up_interruptible(&port->port.open_wait); + tty_port_hangup(&port->port); } diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c index fcf1ec77450..1f5c21ec4b1 100644 --- a/drivers/char/synclinkmp.c +++ b/drivers/char/synclinkmp.c @@ -3331,6 +3331,17 @@ static int carrier_raised(struct tty_port *port) return (info->serial_signals & SerialSignal_DCD) ? 1 : 0; } +static void raise_dtr_rts(struct tty_port *port) +{ + SLMP_INFO *info = container_of(port, SLMP_INFO, port); + unsigned long flags; + + spin_lock_irqsave(&info->lock,flags); + info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR; + set_signals(info); + spin_unlock_irqrestore(&info->lock,flags); +} + /* Block the current process until the specified port is ready to open. */ static int block_til_ready(struct tty_struct *tty, struct file *filp, @@ -3381,12 +3392,8 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, port->blocked_open++; while (1) { - if ((tty->termios->c_cflag & CBAUD)) { - spin_lock_irqsave(&info->lock,flags); - info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR; - set_signals(info); - spin_unlock_irqrestore(&info->lock,flags); - } + if (tty->termios->c_cflag & CBAUD) + tty_port_raise_dtr_rts(port); set_current_state(TASK_INTERRUPTIBLE); @@ -3793,6 +3800,7 @@ static void add_device(SLMP_INFO *info) static const struct tty_port_operations port_ops = { .carrier_raised = carrier_raised, + .raise_dtr_rts = raise_dtr_rts, }; /* Allocate and initialize a device instance structure diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index 0557b638474..9f418bca4a2 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -95,6 +96,29 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) } EXPORT_SYMBOL(tty_port_tty_set); +/** + * tty_port_hangup - hangup helper + * @port: tty port + * + * Perform port level tty hangup flag and count changes. Drop the tty + * reference. + */ + +void tty_port_hangup(struct tty_port *port) +{ + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + port->count = 0; + port->flags &= ~ASYNC_NORMAL_ACTIVE; + if (port->tty) + tty_kref_put(port->tty); + port->tty = NULL; + spin_unlock_irqrestore(&port->lock, flags); + wake_up_interruptible(&port->open_wait); +} +EXPORT_SYMBOL(tty_port_hangup); + /** * tty_port_carrier_raised - carrier raised check * @port: tty port diff --git a/include/linux/tty.h b/include/linux/tty.h index 5001bbcacff..a1a93140e6e 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -438,6 +438,7 @@ extern struct tty_struct *tty_port_tty_get(struct tty_port *port); extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); extern int tty_port_carrier_raised(struct tty_port *port); extern void tty_port_raise_dtr_rts(struct tty_port *port); +extern void tty_port_hangup(struct tty_port *port); extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc); extern int tty_unregister_ldisc(int disc); -- 2.41.0