jack & full duplex possible

I was wondering if it's possible to use Jack?

Yes.

If yes, is full duplex (in & out) possible?

Yes.

What can I expect for the latency (less than 20ms, more than 100 ms)?

Don't know, I've never tested latency in Jack. ALSA gives me 6 - 7 ms.

If not, with Alsa is it possible to have analog in & analog out working at the same time?

Yes.

--

Ragnar

Wonderful! Is it better to use Alsa (less CPU, lower latency)? I was wondering if it is also a good idea to run everything in root (I know it's never a good idea normally) - but for getting the best performance out of the raspberry pi... Should I try to apply those modifications: http://wiki.linuxaudio.org/wiki/raspberrypi

Thanks!

Ok make sense (using Ubuntu Studio for cross compiling and raspbian for the actuel distro)! In the meantime I found this tutorial: Talk Unafraid » Real Time kernels and audio on the Raspberry Pi - but I have to say that I would very much like to use your solution because I also want a similar setup (usb midi, pure data).

Keep in touch!

Hi Pat,

next weekend there will be more information on how to compile the 3.12 kernel with rt-preemption and wolfson drivers included on my website. Please be patient and

Have fun.

Here we go:

http://blog.georgmill.de/2014/04/26/compile-wolfson-audio-card-driver-for-kernel-3-12-y/

Have fun.

I have problem:

git reset --hard 4639d2b773b318d4b0409f67d3d5e73a513ba64b

fatal: Could not parse object '4639d2b773b318d4b0409f67d3d5e73a513ba64b'.

Hi Georg!

Thank you so much for this. Will try to find the time asap to confirm that it's working. With your permission, I will upload the rt-kernel with module so that people can simply do Step 53 (or maybe you already share the files somewhere)?

Talk to you soon

@ Jan Tomasik

Hi Jan,

what does

git status

say?

Georg

I tried both, of course, it's always the same:

git reset --hard 4639d2b773b318d4b0409f67d3d5e73a513ba64b

fatal: Could not parse object '4639d2b773b318d4b0409f67d3d5e73a513ba64b'.

the object does not exist.

git status

# On branch rpi-3.12.y

nothing to commit (working directory clean)

Hi Jan,

you are right. Maybe I made a mistake with git and now have the gravity (movie) effect: Detached sources and lost in space? ;-)

Hope there is time enough to find a solution for that soon. I'll let you know.

Georg (without having fun)

Hi Jan,

please have a look at http://blog.georgmill.de/2014/04/29/compile-wolfson-audio-card-driver-for-kernel-3-12-y-a-new-try/

Test and report,  please. Here I'm able to use the Wolfson card full duplex with jackd and calf-plugins. I routed the two onboard mics through calf reverb and then trough calf phaser to system playback. What an echooooooooo ;-)

With much more fun than ever !

Many thanks Georg

I used your kernel source code to create patch for Runeaudio with Wolfson Audio Card and Power-on-off circuit.

The only problem is in boot with "vc_cma: dma_declare_contiguous (11800000, d400000) failed", I used the workaround described in http://archlinuxarm.org/forum/viewtopic.php?f=31&t=6432

Otherwise, it works great, thanks for the great work.

Re: Instructions for compiling the wolfson audio card kernel drivers and supported use cases

Many thanks Georg

I used your kernel source code to create patch for Runeaudio with Wolfson Audio Card and Power-on-off circuit.

The only problem is in boot with "vc_cma: dma_declare_contiguous (11800000, d400000) failed", I used the workaround described in http://archlinuxarm.org/forum/viewtopic.php?f=31&t=6432

Otherwise, it works great, thanks for the great work.

Re: Instructions for compiling the wolfson audio card kernel drivers and supported use cases