serdev: ttyport: enforce tty-driver open() requirement

[ Upstream commit dee7d0f3b200c67c6ee96bd37c6e8fa52690ab56 ]

The tty-driver open routine is mandatory, but the serdev
tty-port-controller implementation did not treat it as such and would
instead fall back to calling tty_port_open() directly.

Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
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 7f785d7..69fc6d9 100644 (file)
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -120,10 +120,10 @@ static int ttyport_open(struct serdev_controller *ctrl)
                return PTR_ERR(tty);
        serport->tty = tty;
 
-       if (tty->ops->open)
-               tty->ops->open(serport->tty, NULL);
-       else
-               tty_port_open(serport->port, tty, NULL);
+       if (!tty->ops->open)
+               goto err_unlock;
+
+       tty->ops->open(serport->tty, NULL);
 
        /* Bring the UART into a known 8 bits no parity hw fc state */
        ktermios = tty->termios;
@@ -140,6 +140,12 @@ static int ttyport_open(struct serdev_controller *ctrl)
 
        tty_unlock(serport->tty);
        return 0;
+
+err_unlock:
+       tty_unlock(tty);
+       tty_release_struct(tty, serport->tty_idx);
+
+       return -ENODEV;
 }
 
 static void ttyport_close(struct serdev_controller *ctrl)