serial: sccnxp: Fix error handling in sccnxp_probe()

sccnxp_probe() returns result of regulator_disable() that may lead
to returning zero, while device is not properly initialized.
Also the driver enables clocks, but it does not disable it.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index cdd2f942317c59fe4ec04c022a004d871f551fde..b9c7a904c1eaf7716d2137d5bcded2a8c805c17d 100644 (file)
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -889,7 +889,16 @@ static int sccnxp_probe(struct platform_device *pdev)
                        goto err_out;
                uartclk = 0;
        } else {
-               clk_prepare_enable(clk);
+               ret = clk_prepare_enable(clk);
+               if (ret)
+                       goto err_out;
+
+               ret = devm_add_action_or_reset(&pdev->dev,
+                               (void(*)(void *))clk_disable_unprepare,
+                               clk);
+               if (ret)
+                       goto err_out;
+
                uartclk = clk_get_rate(clk);
        }
 
@@ -988,7 +997,7 @@ static int sccnxp_probe(struct platform_device *pdev)
        uart_unregister_driver(&s->uart);
 err_out:
        if (!IS_ERR(s->regulator))
-               return regulator_disable(s->regulator);
+               regulator_disable(s->regulator);
 
        return ret;
 }