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path: root/drivers/tty/serial/serial_core.c
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Diffstat (limited to 'drivers/tty/serial/serial_core.c')
-rw-r--r--drivers/tty/serial/serial_core.c66
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)