Comment 19 for bug 1611831

That indicates the bug is either already fixed in upstream 4.4.16 or it's an Ubuntu specific bug.

To confirm it's now fixed upstream, can you test 4.4.15. It should contain the bug, since Ubuntu 4.4.0-34 had those stable updates and not the 4.4.16 stable updates.

The 4.4.15 kernel can be downloaded from:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.15/

Another testing option would be to test the Xenial -proposed kernel. Xenial -proposed now does have the v4.4.16 stable updates.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed.

Thank you in advance!