serdev: ttyport: add missing open() error handling

Add missing error handling for tty-driver open() which may fail (e.g. if
resource allocation fails or if a port is being disconnected).

Note that close() must be called also in case of failed open() and that
the operation sanity check is amended to catch buggy drivers.

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index 404f3fd070a76166a7ed8eaf7168e2aee182d1eb..5b09ce920117b7375c4b2e171d30e1b01f9578fe 100644 (file)
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -96,16 +96,21 @@ static int ttyport_open(struct serdev_controller *ctrl)
        struct serport *serport = serdev_controller_get_drvdata(ctrl);
        struct tty_struct *tty;
        struct ktermios ktermios;
+       int ret;
 
        tty = tty_init_dev(serport->tty_drv, serport->tty_idx);
        if (IS_ERR(tty))
                return PTR_ERR(tty);
        serport->tty = tty;
 
-       if (!tty->ops->open)
+       if (!tty->ops->open || !tty->ops->close) {
+               ret = -ENODEV;
                goto err_unlock;
+       }
 
-       tty->ops->open(serport->tty, NULL);
+       ret = tty->ops->open(serport->tty, NULL);
+       if (ret)
+               goto err_close;
 
        /* Bring the UART into a known 8 bits no parity hw fc state */
        ktermios = tty->termios;
@@ -123,11 +128,13 @@ static int ttyport_open(struct serdev_controller *ctrl)
        tty_unlock(serport->tty);
        return 0;
 
+err_close:
+       tty->ops->close(tty, NULL);
 err_unlock:
        tty_unlock(tty);
        tty_release_struct(tty, serport->tty_idx);
 
-       return -ENODEV;
+       return ret;
 }
 
 static void ttyport_close(struct serdev_controller *ctrl)