The following code snippet fails on Linux:

QBluetoothAddress remote("11:22:33:44:55:66");

QLowEnergyController controlA(remote);
controlA.connectToDevice();
QVERIFY(controlA.state == ConnectedState);

QLowEnergyController controlB(remote);
controlB.connectToDevice();
QVERIFY(controlB.state == ConnectedState);

The second connectToDevice() fails as long as A maintains its connection. This is due to the fact that only one LLCP connection can be maintained to the remote device. What is required is some form of connection sharing. Presumably with proper Bluez/client API support this could work. However at the time of the implementaiton there was no such API.

This does work on Android. The tst_QLowEnergyController::tst_concurrentDiscovery() function verifies the current/wrong behavior on Linux.