The fixes for LP#1405807 are now in trusty-proposed for both linux-lts-utopic and -vivid, so if you could confirm the kernels there resolve the issue for you, that would help a lot.
The fixes for LP#1405807 are now in trusty-proposed for both linux-lts-utopic and -vivid, so if you could confirm the kernels there resolve the issue for you, that would help a lot.