Hi Felipe, On Tue, Nov 29, 2016 at 2:19 PM, Felipe Ferreri Tonello <eu@xxxxxxxxxxxxxxxxx> wrote: > Hi all, > > Ping on this? > > I already have a v2 ready but waiting for more comments to send. > > More comments below. > > On 21/11/16 12:25, Felipe Ferreri Tonello wrote: >> Hi Luiz, >> >> On November 21, 2016 11:47:04 AM GMT+00:00, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote: >>> Hi Felipe, >>> >>> On Mon, Nov 21, 2016 at 1:21 PM, Felipe Ferreri Tonello >>> <eu@xxxxxxxxxxxxxxxxx> wrote: >>>> Hi all, >>>> >>>> On 18/11/16 14:59, Felipe F. Tonello wrote: >>>>> This plugin implements the Central roli of MIDI over Bluetooth >>>>> Low-Energy (BLE-MIDI) 1.0 specification as published by MMA in >>>>> November/2015. >>>>> >>>>> It was implmemented as a bluez plugin because of latency >>> requirements >>>>> of MIDI. There are still room for improvements on this regard. >>>>> >>>>> Since all parsing and state-machine code is in libmidi.[hc] it >>> should be >>>>> simple to implement Peripheral role as a GATT service as well. >>>>> >>>>> I have also implemented several unit-tests that can be easily >>> extended >>>>> without adding any code, just use-cases. >>>>> >>>>> Files added: >>>>> * profiles/midi/midi.c: Actual GATT plugin >>>>> * profiles/midi/libmidi.[ch]: MIDI parsers >>>>> * unit/test-midi.c: Unit-tests >>> >>> Btw, usually we stayed away from alsa/audio dependencies since they >>> are quite time sensitive which may impact in the responsiveness of >>> bluetoothd, so I wonder if you document anything in this regard? Also >>> please keep in mind many parts of bluetoothd are not thread-safe so if >>> there are other threads involved Im afraid we won't be taking more >>> than the GATT plugin leaving the remaining code to be done somewhere >>> else. >> >> Yes, this is time sensitive, as it requires low-latency connection intervals, but I didn't notice any problems with it. I have tested with two devices connected at the same time and it works very well. What sort of document are you referring to? >> As this profile is quite unique in terms of low-latency GATT services it may be interesting to optimise it in future if necessary. >> >> On the thread note, I was aware of this and implemented in a way thst doesn't require any extra threads. > > This plugin doesn't require any new threads. It relies on notifications > from a device to parse and render proper events that are queued in the > kernel, causing no blocks at all. Even if an error occur, it will be > handled and returned control to bluetoothd. > > It also adds a new file descriptor to be read using struct io. That is > necessary to read events from applications and render raw BLE packets to > be sent to the device with a write without response command. It doesn't > block as well. > > Even though this adds a new dependency, ALSA, it is not an audio plugin. > It is rather a MIDI plugin, which is a byte stream protocol with low > throughput but requires low-latency. Please add this to the commit message of the v2, I will be checking for other problems when applying it. Luiz Augusto von Dentz -- 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
