Similar error messages¹ are filed in both bugs 1408963 and 1390709. In both cases, there were workarounds to network-manager and wpa- supplicant. So, there seems no kernel issue in all three cases.
¹wlan0: deauthenticating from ... by local choice (Reason: 3=DEAUTH_LEAVING) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1386863 Title: 10ec:818b [Lenovo ThinkPad T440] WiFi does not reconnect after resuming from sleep in Ubuntu 14.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386863/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs