Hi Neil, On Thu, Jun 25, 2015 at 2:53 PM, Neil Martin <neil@xxxxxxx> wrote: > Hi, > > I've noticed that the bluetoothd console output shows a steady stream > of RSSI updates, yet only a fraction of these seem to translate into a > DBus PropertiesChanged signal. > > I've just seen 50 or so messages from bluetoothd of the form: > > bluetoothd[3867]: src/adapter.c:device_found_callback() hci0 addr > D0:4F:7E:2B:74:31, rssi -91 flags 0x0000 eir_len 15 > > while only seeing a single PropertiesChanged signal from dbus-monitor > with an RSSI update. That's because by default there is a threshold of 8db: #define RSSI_THRESHOLD 8 http://git.kernel.org/cgit/bluetooth/bluez.git/tree/src/device.c#n88 So if RSSI is changed less than 8dB you don't get any updates through D-Bus. If you want to get updates through D-Bus, you should call SetDiscoveryFilter first, see doc: "If one or more discovery filters have been set, the RSSI delta-threshold, that is imposed by StartDiscovery by default, will not be applied." http://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc/adapter-api.txt#n48 Can I ask what kind of controller do you use ? Some just don't do packet deduplication during scan, and would report all packets received, that would explain flow of events from kernel. Jakub > > Neil > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
