Add __must_check attribute to iio_device_claim_direct_mode(). Since we have now DEFINE_GUARD(iio_claim_direct, ..., iio_device_claim_direct_mode, ...), it is possible to write: guard(iio_claim_direct)(indio_dev); This would be a bug, since the return value is not checked. Adding __must_check to iio_device_claim_direct_mode() makes the compiler emit a warning for the above code. Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> --- This comes from the suggestion at the end of [1]. It seems like a reasonable thing to do regardless if the other series works out or not, so submitting it separately. [1]: https://lore.kernel.org/all/66fcac2dbde60_964f229426@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch/ --- include/linux/iio/iio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 18779b631e90..2dc6470d20a4 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -659,7 +659,7 @@ void iio_device_unregister(struct iio_dev *indio_dev); int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev, struct module *this_mod); int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp); -int iio_device_claim_direct_mode(struct iio_dev *indio_dev); +__must_check int iio_device_claim_direct_mode(struct iio_dev *indio_dev); void iio_device_release_direct_mode(struct iio_dev *indio_dev); /* --- base-commit: 431c39f6d3edbab14f48dbf37a58ccdc0ac3be1e change-id: 20241002-iio-must-check-claim-direct-e6988a195368 Best regards, -- David Lechner <dlechner@xxxxxxxxxxxx>