diff options
| -rw-r--r-- | drivers/char/isicom.c | 79 | ||||
| -rw-r--r-- | drivers/char/mxser.c | 71 | ||||
| -rw-r--r-- | drivers/char/riscom8.c | 86 | ||||
| -rw-r--r-- | drivers/char/synclink.c | 1 | ||||
| -rw-r--r-- | drivers/char/tty_port.c | 105 | ||||
| -rw-r--r-- | drivers/char/vme_scc.c | 6 | ||||
| -rw-r--r-- | include/linux/tty.h | 2 |
7 files changed, 115 insertions, 235 deletions
diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c index db53db91ae4..bac55cf4424 100644 --- a/drivers/char/isicom.c +++ b/drivers/char/isicom.c @@ -838,82 +838,6 @@ static int isicom_carrier_raised(struct tty_port *port) return (ip->status & ISI_DCD)?1 : 0; } -static int block_til_ready(struct tty_struct *tty, struct file *filp, - struct isi_port *ip) -{ - struct tty_port *port = &ip->port; - int do_clocal = 0, retval; - unsigned long flags; - DECLARE_WAITQUEUE(wait, current); - int cd; - - /* block if port is in the process of being closed */ - - if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { - pr_dbg("block_til_ready: close in progress.\n"); - interruptible_sleep_on(&port->close_wait); - if (port->flags & ASYNC_HUP_NOTIFY) - return -EAGAIN; - else - return -ERESTARTSYS; - } - - /* if non-blocking mode is set ... */ - - if ((filp->f_flags & O_NONBLOCK) || - (tty->flags & (1 << TTY_IO_ERROR))) { - pr_dbg("block_til_ready: non-block mode.\n"); - port->flags |= ASYNC_NORMAL_ACTIVE; - return 0; - } - - if (C_CLOCAL(tty)) - do_clocal = 1; - - /* block waiting for DCD to be asserted, and while - callout dev is busy */ - retval = 0; - add_wait_queue(&port->open_wait, &wait); - - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count--; - port->blocked_open++; - spin_unlock_irqrestore(&port->lock, flags); - - while (1) { - tty_port_raise_dtr_rts(port); - - set_current_state(TASK_INTERRUPTIBLE); - if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) { - if (port->flags & ASYNC_HUP_NOTIFY) - retval = -EAGAIN; - else - retval = -ERESTARTSYS; - break; - } - cd = tty_port_carrier_raised(port); - if (!(port->flags & ASYNC_CLOSING) && - (do_clocal || cd)) - break; - if (signal_pending(current)) { - retval = -ERESTARTSYS; - break; - } - schedule(); - } - set_current_state(TASK_RUNNING); - remove_wait_queue(&port->open_wait, &wait); - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count++; - port->blocked_open--; - if (retval == 0) - port->flags |= ASYNC_NORMAL_ACTIVE; - spin_unlock_irqrestore(&port->lock, flags); - return 0; -} - static int isicom_open(struct tty_struct *tty, struct file *filp) { struct isi_port *port; @@ -940,12 +864,13 @@ static int isicom_open(struct tty_struct *tty, struct file *filp) isicom_setup_board(card); + /* FIXME: locking on port.count etc */ port->port.count++; tty->driver_data = port; tty_port_tty_set(&port->port, tty); error = isicom_setup_port(tty); if (error == 0) - error = block_til_ready(tty, filp, port); + error = tty_port_block_til_ready(&port->port, tty, filp); return error; } diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c index e2471cf1ee9..08ba6eb1a38 100644 --- a/drivers/char/mxser.c +++ b/drivers/char/mxser.c @@ -558,75 +558,6 @@ static void mxser_raise_dtr_rts(struct tty_port *port) spin_unlock_irqrestore(&mp->slock, flags); } -static int mxser_block_til_ready(struct tty_struct *tty, struct file *filp, - struct mxser_port *mp) -{ - DECLARE_WAITQUEUE(wait, current); - int retval; - int do_clocal = 0; - unsigned long flags; - int cd; - struct tty_port *port = &mp->port; - - /* - * If non-blocking mode is set, or the port is not enabled, - * then make the check up front and then exit. - */ - if ((filp->f_flags & O_NONBLOCK) || - test_bit(TTY_IO_ERROR, &tty->flags)) { - port->flags |= ASYNC_NORMAL_ACTIVE; - return 0; - } - - if (tty->termios->c_cflag & CLOCAL) - do_clocal = 1; - - /* - * Block waiting for the carrier detect and the line to become - * free (i.e., not in use by the callout). While we are in - * this loop, port->count is dropped by one, so that - * mxser_close() knows when to free things. We restore it upon - * exit, either normal or abnormal. - */ - retval = 0; - add_wait_queue(&port->open_wait, &wait); - - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count--; - port->blocked_open++; - spin_unlock_irqrestore(&port->lock, flags); - while (1) { - tty_port_raise_dtr_rts(port); - set_current_state(TASK_INTERRUPTIBLE); - if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) { - if (port->flags & ASYNC_HUP_NOTIFY) - retval = -EAGAIN; - else - retval = -ERESTARTSYS; - break; - } - cd = tty_port_carrier_raised(port); - if (!(port->flags & ASYNC_CLOSING) && (do_clocal || cd)) - break; - if (signal_pending(current)) { - retval = -ERESTARTSYS; - break; - } - schedule(); - } - set_current_state(TASK_RUNNING); - remove_wait_queue(&port->open_wait, &wait); - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count++; - port->blocked_open--; - if (retval == 0) - port->flags |= ASYNC_NORMAL_ACTIVE; - spin_unlock_irqrestore(&port->lock, flags); - return 0; -} - static int mxser_set_baud(struct tty_struct *tty, long newspd) { struct mxser_port *info = tty->driver_data; @@ -1110,7 +1041,7 @@ static int mxser_open(struct tty_struct *tty, struct file *filp) if (retval) return retval; - retval = mxser_block_til_ready(tty, filp, info); + retval = tty_port_block_til_ready(&info->port, tty, filp); if (retval) return retval; diff --git a/drivers/char/riscom8.c b/drivers/char/riscom8.c index 14662d7aa62..af34c2054a0 100644 --- a/drivers/char/riscom8.c +++ b/drivers/char/riscom8.c @@ -874,90 +874,6 @@ static int carrier_raised(struct tty_port *port) return CD; } -static int block_til_ready(struct tty_struct *tty, struct file *filp, - struct riscom_port *rp) -{ - DECLARE_WAITQUEUE(wait, current); - int retval; - int do_clocal = 0; - int CD; - unsigned long flags; - struct tty_port *port = &rp->port; - - /* - * If the device is in the middle of being closed, then block - * until it's done, and then try again. - */ - if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { - interruptible_sleep_on(&port->close_wait); - if (port->flags & ASYNC_HUP_NOTIFY) - return -EAGAIN; - else - return -ERESTARTSYS; - } - - /* - * If non-blocking mode is set, or the port is not enabled, - * then make the check up front and then exit. - */ - if ((filp->f_flags & O_NONBLOCK) || - (tty->flags & (1 << TTY_IO_ERROR))) { - port->flags |= ASYNC_NORMAL_ACTIVE; - return 0; - } - - if (C_CLOCAL(tty)) - do_clocal = 1; - - /* - * Block waiting for the carrier detect and the line to become - * free (i.e., not in use by the callout). While we are in - * this loop, info->count is dropped by one, so that - * rs_close() knows when to free things. We restore it upon - * exit, either normal or abnormal. - */ - retval = 0; - add_wait_queue(&port->open_wait, &wait); - - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count--; - port->blocked_open++; - spin_unlock_irqrestore(&port->lock, flags); - - while (1) { - - CD = tty_port_carrier_raised(port); - set_current_state(TASK_INTERRUPTIBLE); - if (tty_hung_up_p(filp) || - !(port->flags & ASYNC_INITIALIZED)) { - if (port->flags & ASYNC_HUP_NOTIFY) - retval = -EAGAIN; - else - retval = -ERESTARTSYS; - break; - } - if (!(port->flags & ASYNC_CLOSING) && - (do_clocal || CD)) - break; - if (signal_pending(current)) { - retval = -ERESTARTSYS; - break; - } - schedule(); - } - __set_current_state(TASK_RUNNING); - remove_wait_queue(&port->open_wait, &wait); - spin_lock_irqsave(&port->lock, flags); - if (!tty_hung_up_p(filp)) - port->count++; - port->blocked_open--; - if (retval == 0) - port->flags |= ASYNC_NORMAL_ACTIVE; - spin_unlock_irqrestore(&port->lock, flags); - return 0; -} - static int rc_open(struct tty_struct *tty, struct file *filp) { int board; @@ -984,7 +900,7 @@ static int rc_open(struct tty_struct *tty, struct file *filp) error = rc_setup_port(bp, port); if (error == 0) - error = block_til_ready(tty, filp, port); + error = tty_port_block_til_ready(&port->port, tty, filp); return error; } diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c index ac9f21e18c3..0ded4ed3da3 100644 --- a/drivers/char/synclink.c +++ b/drivers/char/synclink.c @@ -3401,6 +3401,7 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, set_current_state(TASK_RUNNING); remove_wait_queue(&port->open_wait, &wait); + /* FIXME: Racy on hangup during close wait */ if (extra_count) port->count++; port->blocked_open--; diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index 9f418bca4a2..ff94182b381 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -151,3 +151,108 @@ void tty_port_raise_dtr_rts(struct tty_port *port) port->ops->raise_dtr_rts(port); } EXPORT_SYMBOL(tty_port_raise_dtr_rts); + +/** + * tty_port_block_til_ready - Waiting logic for tty open + * @port: the tty port being opened + * @tty: the tty device being bound + * @filp: the file pointer of the opener + * + * Implement the core POSIX/SuS tty behaviour when opening a tty device. + * Handles: + * - hangup (both before and during) + * - non blocking open + * - rts/dtr/dcd + * - signals + * - port flags and counts + * + * The passed tty_port must implement the carrier_raised method if it can + * do carrier detect and the raise_dtr_rts method if it supports software + * 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) +{ + int do_clocal = 0, retval; + unsigned long flags; + DECLARE_WAITQUEUE(wait, current); + int cd; + + /* block if port is in the process of being closed */ + if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { + interruptible_sleep_on(&port->close_wait); + if (port->flags & ASYNC_HUP_NOTIFY) + return -EAGAIN; + else + return -ERESTARTSYS; + } + + /* if non-blocking mode is set we can pass directly to open unless + the port has just hung up or is in another error state */ + if ((filp->f_flags & O_NONBLOCK) || + (tty->flags & (1 << TTY_IO_ERROR))) { + port->flags |= ASYNC_NORMAL_ACTIVE; + return 0; + } + + if (C_CLOCAL(tty)) + do_clocal = 1; + + /* Block waiting until we can proceed. We may need to wait for the + carrier, but we must also wait for any close that is in progress + before the next open may complete */ + + retval = 0; + add_wait_queue(&port->open_wait, &wait); + + /* The port lock protects the port counts */ + spin_lock_irqsave(&port->lock, flags); + if (!tty_hung_up_p(filp)) + port->count--; + port->blocked_open++; + spin_unlock_irqrestore(&port->lock, flags); + + while (1) { + /* Indicate we are open */ + tty_port_raise_dtr_rts(port); + + set_current_state(TASK_INTERRUPTIBLE); + /* 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; + else + retval = -ERESTARTSYS; + break; + } + /* Probe the carrier. For devices with no carrier detect this + will always return true */ + cd = tty_port_carrier_raised(port); + if (!(port->flags & ASYNC_CLOSING) && + (do_clocal || cd)) + break; + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + schedule(); + } + set_current_state(TASK_RUNNING); + remove_wait_queue(&port->open_wait, &wait); + + /* Update counts. A parallel hangup will have set count to zero and + we must not mess that up further */ + spin_lock_irqsave(&port->lock, flags); + if (!tty_hung_up_p(filp)) + port->count++; + port->blocked_open--; + if (retval == 0) + port->flags |= ASYNC_NORMAL_ACTIVE; + spin_unlock_irqrestore(&port->lock, flags); + return 0; + +} +EXPORT_SYMBOL(tty_port_block_til_ready); + diff --git a/drivers/char/vme_scc.c b/drivers/char/vme_scc.c index d4e1534c0e0..2d9242a45a0 100644 --- a/drivers/char/vme_scc.c +++ b/drivers/char/vme_scc.c @@ -631,8 +631,8 @@ static void scc_enable_rx_interrupts(void *ptr) static int scc_carrier_raised(struct tty_port *port) { - struct scc_port *scc = container_of(port, struct scc_port, gs.port); - unsigned channel = port->channel; + struct scc_port *sc = container_of(port, struct scc_port, gs.port); + unsigned channel = sc->channel; return !!(scc_last_status_reg[channel] & SR_DCD); } @@ -643,7 +643,7 @@ static void scc_shutdown_port(void *ptr) struct scc_port *port = ptr; port->gs.port.flags &= ~ GS_ACTIVE; - if (port->gs.port.tty && port->gs.port.tty->termios->c_cflag & HUPCL) { + if (port->gs.port.tty && (port->gs.port.tty->termios->c_cflag & HUPCL)) { scc_setsignals (port, 0, 0); } } diff --git a/include/linux/tty.h b/include/linux/tty.h index a1a93140e6e..61a0ab32cf1 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -439,6 +439,8 @@ 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_port_block_til_ready(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); |