[PATCH 4.9 140/310] gpio: label descriptors using the device name

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Linus Walleij <linus.walleij@xxxxxxxxxx>


[ Upstream commit 24e78079bf2250874e33da2e7cfbb6db72d3caf4 ]

Some GPIO lines appear named "?" in the lsgpio dump due to their
requesting drivers not passing a reasonable label.

Most typically this happens if a device tree node just defines
gpios = <...> and not foo-gpios = <...>, the former gets named
"foo" and the latter gets named "?".

However the struct device passed in is always valid so let's
just label the GPIO with dev_name() on the device if no proper
label was passed.

Cc: Reported-by: Jason Kridner <jkridner@xxxxxxxxxxxxxxx>
Reported-by: Jason Kridner <jkridner@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpio/gpiolib.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3231,7 +3231,8 @@ struct gpio_desc *__must_check gpiod_get
 		return desc;
 	}
 
-	status = gpiod_request(desc, con_id);
+	/* 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 (status < 0)
 		return ERR_PTR(status);