Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
From:   Andrey Batyiev <batyiev@gmail.com>
Date:   Wed, 8 Jul 2020 13:24:32 +0300
Message-ID: <CAEQQxWxKs7ewwVyq4mnsyLbRhErQe9vZc5joNK6zfGSO3wN5bg@mail.gmail.com>
Subject: Temporary device removal during discovery
To:     linux-bluetooth <linux-bluetooth@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hello everyone,

I've found the following issue:
1. in bluetoothctl run "power on", "scan on"
2. discovery is now permanent
3. make one device discoverable for a moment (e.g. turn bluetooth on
on your phone)
4. bluez would detect new device
5. turn bluetooth off on your phone
6. now wait

Expected result:
7. your phone should disappear from discovered set after some time

Actual result:
7. phone would stay there until discovery is off (i.e. "scan off" in
bluetoothctl)


It seems like there is a code in src/adapter.c responsible for purge
stale entries
(remove_temp_devices), however it only triggers when discovery is off
(and after 3 mins).


My use case is to continuously monitor the bluetooth environment. Is
it bluez responsibility to
remove stale entries during discovery or should my own app repeatedly
stop discovery?

Thanks,
   Andrey