This exact bug happens all the time for me on calls for more than around 2min. The Bluetooth connection fail also happens during dialling - often on the first call after a connection is established.
The only way to re-establish a connection is to disable bluetooth and then re-enable it, and the fastest way to ensure it works is to put the phone in flight mode and then turn that off again. device: bq Aquaris E4.5 OS build number: OTA-10.1 Ubuntu Image part: 20160408.4 Ubuntu build description: Ubuntu 15.04 - armhf(20160408-211605) Customisation Image part: 20160324--36-54-vivid Car: Skoda Octavia 2013 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to bluez in Ubuntu. https://bugs.launchpad.net/bugs/1555608 Title: Bluetooth "Connection timed out" during a longer call Status in Canonical System Image: Confirmed Status in bluez package in Ubuntu: Confirmed Bug description: Issue: Phone disconnected bluetooth connection during a longer call. I am on: current build number: 275 device name: krillin channel: ubuntu-touch/rc-proposed/bq-aquaris.en last update: 2016-03-08 06:14:58 version version: 275 version ubuntu: 20160308 version device: 20160108-efc96d8 version custom: 20160111-926-36--vivid I was in a longer telephone call. All of a sudden the bluetooth connection got interrupted. At the time when the bluetooth connection got disconnected the following statement from bluetooth was logged: Mar 9 08:26:31 ubuntu-phablet bluetoothd[899]: Start: Connection timed out (110) + following logs (see attached) The call itself still was active just the phone disconnected from my car. Logs are attached. Matthias To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1555608/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp