Car stereo does not connect via Bluetooth after phone power-on if visibility is OFF

[vige]

@jovirkku

In this bug report, the Bluetooth system of the car attempts to connect to the phone. It fails if visibility is turned off. If visibility is enabled then the car can connect to the phone. The phone works in the way it is intended to work.

I don’t think that’s the case here:

@smokku

You can enable visibility and disable immediately. Then the car stereo is able to connect without problem.

The car connects to phone fine even without the phone being visible, as the car already knows what the mac address of the phone is.

I believe this is the same problem that I have been having, and also many others. The bug has several symptoms, so the bug reports end up being a bit different as everyone describes the symptoms that they have noticed. See:

• [4.4.0.64][Xperia 10 III] Bluetooth pairing does not show device name after first pairing
• [Xperia 10 iii][4.4.0.64] Bluetooth auto connection delays
• No bluetooth auto connect on Xperia 10 III
• Bluetooth Speaker stuttering + problems with automatic reconnecting

I myself used to suffer from this on 4.4, then I didn’t have it on 4.5 and now it appeared again on 4.6.

I spent quite a lot of time debugging this when I was on 4.4. The issue is, or at least it was then, that something rfkills bluetooth while it is being initialized. I couldn’t figure out what was causing it, but it is very timing sensitive - even small changes in the bootup sequence could change this, which is probably why I didn’t see it happen on 4.5. I believe it was just good luck, which has now run out. I haven’t really tried debugging it on 4.6, but the symptoms are really similar so I believe it’s the same bug.