On Tue, Dec 5, 2017 at 10:08 AM Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > > What about the case when the data_available element in > > iio_buffer_access_funcs is undefined (e.g. industrialio-buffer-cb)? > > Do we modify iio_buffer_data_available() to return 0, do we make the > > sysfs function return -ENOENT or -EINVAL, or simply not expose the sysfs > > interface for this case? > > The callback buffer does not support any of the interfaces required for the > userspace facing side. E.g. there is no read() callback. > > For proper support of the userspace interfaces data_available() is required, > otherwise read() would never return. So I think this is fine, we'd never > register the userspacing interface if it didn't have the data_available > callback. So there should already be provisions in place for *not* registering the cb buffer with user-space, meaning no additional logic would be required for exposing / not exposing a "data_available" sysfs attribute, correct? Assuming the above is correct, I'll come back with a generic v2 of this. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
