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 <[email protected]> Reported-by: Dr. H. Nikolaus Schaller <[email protected]> --- drivers/gpio/gpiolib.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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 @@ static int gpiod_request(struct gpio_desc *desc, const char *label) 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 @@ static int gpiod_request(struct gpio_desc *desc, const char *label) spin_lock_irqsave(&gpio_lock, flags); chip = desc->chip; + if (chip == NULL) + goto done; if (!try_module_get(chip->owner)) goto done; -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
