gpio: No NULL owner

commit 7d18f0a14aa6a0d6bad39111c1fb655f07f71d59 upstream.

Sometimes a GPIO is fetched with NULL as parent device, and
that is just fine. So under these circumstances, avoid using
dev_name() to provide a name for the GPIO line.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 68ea6e712bf90e1ee1c961c88be05b225ea1c977..7e0bfd7347f6ce159bb6da293fbf120727469923 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3313,6 +3313,8 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
        struct gpio_desc *desc = NULL;
        int status;
        enum gpio_lookup_flags lookupflags = 0;
+       /* Maybe we have a device name, maybe not */
+       const char *devname = dev ? dev_name(dev) : "?";
 
        dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
 
@@ -3341,8 +3343,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
                return desc;
        }
 
-       /* If a connection label was passed use that, else use the device name as label */
-       status = gpiod_request(desc, con_id ? con_id : dev_name(dev));
+       /*
+        * If a connection label was passed use that, else attempt to use
+        * the device name as label
+        */
+       status = gpiod_request(desc, con_id ? con_id : devname);
        if (status < 0)
                return ERR_PTR(status);