[PATCH 3.16.y-ckt 026/135] gpiolib: of: Correct error handling in of_get_named_gpiod_flags

[Luis Henriques]

3.16.7-ckt6 -stable review patch.  If anyone has any objections, please let me know.

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

From: Hans Holmberg <hans.holmberg@xxxxxxxxx>

commit 7b8792bbdffdff3abda704f89c6a45ea97afdc62 upstream.

of_get_named_gpiod_flags fails with -EPROBE_DEFER in cases
where the gpio chip is available and the GPIO translation fails.

This causes drivers to be re-probed erroneusly, and hides the
real problem(i.e. the GPIO number being out of range).

Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxxxx>
Reviewed-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/gpio/gpiolib-of.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index af7e25c9a9ae..8f9f0ad91445 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -45,8 +45,14 @@ static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
 		return false;
 
 	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
-	if (ret < 0)
-		return false;
+	if (ret < 0) {
+		/* We've found the gpio chip, but the translation failed.
+		 * Return true to stop looking and return the translation
+		 * error via out_gpio
+		 */
+		gg_data->out_gpio = ERR_PTR(ret);
+		return true;
+	 }
 
 	gg_data->out_gpio = gpiochip_get_desc(gc, ret);
 	return true;
-- 
2.1.4

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