TTY: serial, inline uart_get

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>

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)