serial: 8250_of: fix return code when probe function fails to get reset

The error pointer from devm_reset_control_get_optional_shared() is
not propagated.

One of the most common problem scenarios is it returns -EPROBE_DEFER
when the reset controller has not probed yet.  In this case, the
probe of the reset consumer should be deferred.

Fixes: e2860e1f62f2 ("serial: 8250_of: Add reset support")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 1e67a7e4a5fd..160b8906d9b9 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -136,8 +136,11 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
         }
 
         info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
-        if (IS_ERR(info->rst))
+        if (IS_ERR(info->rst)) {
+                ret = PTR_ERR(info->rst);
                 goto err_dispose;
+        }
+
         ret = reset_control_deassert(info->rst);
         if (ret)
                 goto err_dispose;