EINVAL should be returned only when the requested format is unsupported. On errors when writing the data, let's return EIO, which is the closest description of the situation when we don't inspect it more. Signed-off-by: Milan Zamazal <mzamazal@redhat.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>