sc16is7xx: Check for an error when the clock is enabled.

When the clock is enabled, check if there is an error. Otherwise
clk_get_rate() can be called without enabled clock.

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

Fixes: 0814e8d5da2b ("sc16is7xx: enable the clock")
Signed-off-by: Stefan Potyra <Stefan.Potyra@elektrobit.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 65792a3539d0..243c96025053 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1168,7 +1168,10 @@ static int sc16is7xx_probe(struct device *dev,
                 else
                         return PTR_ERR(s->clk);
         } else {
-                clk_prepare_enable(s->clk);
+                ret = clk_prepare_enable(s->clk);
+                if (ret)
+                        return ret;
+
                 freq = clk_get_rate(s->clk);
         }