gpiolib: of: Correct error handling in of_get_named_gpiod_flags

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).

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Hans Holmberg <hans.holmberg@intel.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 604dbe60bdee..08261f2b3a82 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;