gpiolib: of: Correct error handling in of_get_named_gpiod_flags

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@intel.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 665f953..af909a2 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/device.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/io.h>
@@ -42,8 +43,14 @@ 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 = ret + gc->base;
        return true;