Commit 8853daf3 authored Jul 04, 2018 by Janusz Krzysztofik Committed by Linus Walleij Jul 09, 2018

gpiolib: Defer on non-DT find_chip_by_name() failure

Avoid replication of error code conversion in non-DT GPIO consumers'
code by returning -EPROBE_DEFER from gpiod_find() in case a chip
identified by its label in a registered lookup table is not ready.

See https://lkml.org/lkml/2018/5/30/176

 for example case.

Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

parent 36b31279

drivers/gpio/gpiolib.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -3656,9 +3656,16 @@ static struct gpio_desc gpiod_find(struct device dev, const char *con_id,
		chip = find_chip_by_name(p->chip_label);

		if (!chip) {
		dev_err(dev, "cannot find GPIO chip %s\n",
		/*
		* As the lookup table indicates a chip with
		* p->chip_label should exist, assume it may
		* still appear later and let the interested
		* consumer be probed again or let the Deferred
		* Probe infrastructure handle the error.
		*/
		dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
		p->chip_label);
		return ERR_PTR(-ENODEV);
		return ERR_PTR(-EPROBE_DEFER);
		}

		if (chip->ngpio <= p->chip_hwnum) {