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TTY: serial, inline uart_get

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We need to expand uart_get into uart_open. We need it to move on with
conversion to use tty_port_open helper. After we do this, the code
will be much more similar to what tty_port_open does.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jiri Slaby 2011-11-09 21:33:49 +01:00 committed by Greg Kroah-Hartman
parent b39c49a05e
commit 1c7b13c488
1 changed files with 22 additions and 44 deletions
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66
drivers/tty/serial/serial_core.c
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@ -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)