gpiolib: let gpiod_request() return -EPROBE_DEFER
Patch be1a4b brought some improvements to the GPIO error handling code,
but also changed the return value of gpiod_request() when called on a
not yet initialized GPIO descriptor: it now returns -EINVAL instead of
-EPROBE_DEFER, and this affects some drivers.
This patch restores the original behavior for gpiod_request(). It is
safe to do so now that desc_to_gpio() does not rely on the GPIO
descriptor to be initialized. Other functions changed by patch be1a4b
do not see their return value affected, so these are not reverted.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Dr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f330631..0dee0e0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1398,7 +1398,7 @@
int status = -EPROBE_DEFER;
unsigned long flags;
- if (!desc || !desc->chip) {
+ if (!desc) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1406,6 +1406,8 @@
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
+ if (chip == NULL)
+ goto done;
if (!try_module_get(chip->owner))
goto done;