diff options
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
-rw-r--r-- | drivers/tty/serial/serial_core.c | 66 |
1 files changed, 22 insertions, 44 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 4b1dcd3f2a40..2ca4df4a4836 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1429,33 +1429,6 @@ static void uart_dtr_rts(struct tty_port *port, int onoff) uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); } -static struct uart_state *uart_get(struct uart_driver *drv, int line) -{ - struct uart_state *state; - struct tty_port *port; - int ret = 0; - - state = drv->state + line; - port = &state->port; - if (mutex_lock_interruptible(&port->mutex)) { - ret = -ERESTARTSYS; - goto err; - } - - port->count++; - if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { - ret = -ENXIO; - goto err_unlock; - } - return state; - - err_unlock: - port->count--; - mutex_unlock(&port->mutex); - err: - return ERR_PTR(ret); -} - /* * calls to uart_open are serialised by the BKL in * fs/char_dev.c:chrdev_open() @@ -1469,26 +1442,29 @@ static struct uart_state *uart_get(struct uart_driver *drv, int line) static int uart_open(struct tty_struct *tty, struct file *filp) { struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state; - struct uart_state *state; - struct tty_port *port; int retval, line = tty->index; + struct uart_state *state = drv->state + line; + struct tty_port *port = &state->port; pr_debug("uart_open(%d) called\n", line); /* - * We take the semaphore inside uart_get to guarantee that we won't - * be re-entered while allocating the state structure, or while we - * request any IRQs that the driver may need. This also has the nice - * side-effect that it delays the action of uart_hangup, so we can - * guarantee that state->port.tty will always contain something - * reasonable. + * We take the semaphore here to guarantee that we won't be re-entered + * while allocating the state structure, or while we request any IRQs + * that the driver may need. This also has the nice side-effect that + * it delays the action of uart_hangup, so we can guarantee that + * state->port.tty will always contain something reasonable. */ - state = uart_get(drv, line); - if (IS_ERR(state)) { - retval = PTR_ERR(state); - goto fail; + if (mutex_lock_interruptible(&port->mutex)) { + retval = -ERESTARTSYS; + goto end; + } + + port->count++; + if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { + retval = -ENXIO; + goto err_dec_count; } - port = &state->port; /* * Once we set tty->driver_data here, we are guaranteed that @@ -1505,9 +1481,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp) */ if (tty_hung_up_p(filp)) { retval = -EAGAIN; - port->count--; - mutex_unlock(&port->mutex); - goto fail; + goto err_dec_count; } /* @@ -1528,8 +1502,12 @@ static int uart_open(struct tty_struct *tty, struct file *filp) if (retval == 0) retval = tty_port_block_til_ready(port, tty, filp); -fail: +end: return retval; +err_dec_count: + port->count--; + mutex_unlock(&port->mutex); + goto end; } static const char *uart_type(struct uart_port *port) |