From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Reply-To: snd-bt-sco@corinis.net Message-ID: <41604792.8030309@xmission.com> Date: Sun, 03 Oct 2004 12:40:18 -0600 From: Brad Midgley MIME-Version: 1.0 To: snd-bt-sco@corinis.net, BlueZ Mailing List References: <41603BF5.9030405@superbug.co.uk> In-Reply-To: <41603BF5.9030405@superbug.co.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Subject: Re: [snd-bt-sco] bluetooth headset profile with alsa in user space. List-ID: James, I've looked at this too. I'm crossposting to see if Marcel wants to comment. Some people think bluetooth-alsa should have a smaller kernel footprint and some people think it's the userspace component that needs to be eliminated. The bottom line is that it needs to go in a direction that is acceptable to bluez and alsa but doesn't leave so much to be desired by the bluez group that they feel like reimplementing/rejecting it. the less-kernel-space argument - alsa would not be affected [much] - bluez would only be affected in that we may want hooks to go into libbluetooth - userspace stuff is easier to debug and develop - supporting multiple headsets simultaneously should be more straightforward - kernel developers won't be questioning it - adding it to a linux distro that has bluez already would be easier The more-kernel-space argument: - alsa has said they would consider patches that don't have the userspace entanglements - the bluez project leaders may decide that in-kernel is the way audio has to be done - dbus/hotplug may play nicer with an in-kernel driver I think now the less-kernel-space is safer. Regardless of our approach, apps that want bluetooth-alsa like asterisk will have to be linked with a new library so there's not a disadvantage there with another build requirement. There's probably just too much uncertainty with the in-kernel approach. Brad James Courtier-Dutton wrote: > It is possible to implement an alsa device is user space, without > requiring any kernel modules. An example of this the the pcm_jack.c file > in: > ./alsa-lib/src/pcm/ext/pcm_jack.c > > It basically makes jackd look like a sound card to any alsa application. > > This should help, because the bluetooth profile code is in user space as > well, so we could make the bluetooth profile look like an alsa sound card. > > Any comments? > > James > >