iio: percolate error if event fd fails
This makes the error from iio_event_getfd() percolate up
to userspace properly so we can know for sure there is no
events on this device (-ENODEV returned). Before this patch
we would bail out looking for the unsupported events on the
erroneous (negative) file descriptor.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index b3fcc2c..b347524 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1153,6 +1153,8 @@
if (cmd == IIO_GET_EVENT_FD_IOCTL) {
fd = iio_event_getfd(indio_dev);
+ if (fd < 0)
+ return fd;
if (copy_to_user(ip, &fd, sizeof(fd)))
return -EFAULT;
return 0;