OK, I think I figured it out after looking at a radio log of the problem reproduced by Alfonso.
First, there are a couple of MTK-specific unsolicited events that are received that look suspicious: RIL_UNSOL_RESPONSE_PS_NETWORK_STATE_CHANGED UNSOL_RESTRICTED_STATE_CHANGED RIL_UNSOL_RESPONSE_PS_NETWORK_STATE_CHANGED UNSOL_RESTRICTED_STATE_CHANGED UNSOL_DATA_CALL_LIST_CHANGED Turns the mtkmodem code overrides the normal NETWORK_STATE_CHANGED unsolicted request with the PS_NETWORK_STATE_CHANGED request. The RESTRICTED_STATE_CHANGED request doesn't seem to be listened for at all. That said, I also see a UNSOL_DATA_CALL_LIST_CHANGED with the following payload: 01 00 00 00 F2 03 00 00 09 00 00 00 00 00 00 00 01 00 00 00 = unsolicted F2 03 00 00 = UNSOL_DATA_CALL_LIST_CHANGED 09 00 00 00 = version 00 00 00 00 = number of calls The function ril_gprs_context_call_list_changed() in /drivers/rilmodem /gprs-context.c handles this message. If tries to iterator over the call list, and if disconnect == TRUE, or active_cid_found == FALSE, it calls set_context_disconnect(). This function however only sets the internal rilmodem struct to disconnected state, and doesn't inform the ofono core of the disconnect. So, it leaves the connection internally disconnected, but to the rest of the system, it's still connected. I imagine this may be the same bug as bug #1436427 ( which has been a theory all along ). I'm working on a fix now, and should have something available to test by tomorrow. ** Also affects: ofono (Ubuntu) Importance: Undecided Status: New ** Changed in: ofono (Ubuntu) Status: New => In Progress ** Changed in: ofono (Ubuntu) Importance: Undecided => Critical ** Changed in: ofono (Ubuntu) Assignee: (unassigned) => Tony Espy (awe) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1435328 Title: Leaving Wifi does not connect to mobile carrier data (GSM) To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1435328/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs