Jonathan Cameron [off-list ref] [2021-02-12 19:12:19]:

Hi Jonathan,

quoted

 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.96+ #473

So, we moved this into the core a while back (to avoid exactly this sort of issue).
That change predates this introduction of this driver as it went in
in v5.8

sorry for the noise, I've missed that commit 8525df47b3d1 ("iio: core:
fix/re-introduce back parent assignment"), thank you for the hint.

So I think you've hit an issue with a backport here to an earlier kernel?

Indeed, I've backported it to 5.4.96 as you can see in the dmesg output above.
I'll try to reproduce it again on 5.10 in the upcoming days.

Cheers,

Petr