From: Janusz Krzysztofik Date: Tue, 3 Jul 2018 22:18:19 +0000 (+0200) Subject: gpiolib: Defer on non-DT find_chip_by_name() failure X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8853daf3b4acb3bf8c0244a12b4f58ed5123f449;p=linux.git 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 Signed-off-by: Janusz Krzysztofik Reviewed-by: Boris Brezillon Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8ec51b7777c6b..a9a290999990e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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", - p->chip_label); - return ERR_PTR(-ENODEV); + /* + * 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(-EPROBE_DEFER); } if (chip->ngpio <= p->chip_hwnum) {