Cirrus Audio, B+, and Jack??

Hi

I get the same error with a Raspberry Pi B and Wolfson Audio Card. I'm trying to use jackd to use it with Guitarix and Rakarrack.

BR / Fernando

Here's something that may be relevant:

https://github.com/raspberrypi/linux/commit/bad49c21520ddc40d512a0d424cbc94f20068e6c

As specified on the linux audio wiki (http://wiki.linuxaudio.org/wiki/raspberrypi#using_jack), Jack needs to be patched in order to work correctly, however I did reinstall it from those repositories and haven't really gotten any further.

As far as the code supplied by the first link, can anyone give me pointers on how to build/install that?

Thanks.

I have seen the same error with jack. ALSA's dmix and dsnoop plugins don't work either, they also complain over no mmap in the hardware driver.

It all works on my B Pis with Wolfson cards and the old 3.10 kernel.

 

Here's something that may be relevant:

https://github.com/raspberrypi/linux/commit/bad49c21520ddc40d512a0d424cbc94f20068e6c

Somewhat relevant, that is the commit that added memory mapped I/O support to the Pi's built-in audio.

It lead me on the right path, though. I looked over the kernel source tree from Cirrus Logic, comparing it with the old 3.10 kernel for the Wolfson card.

I found a regression in sound/soc/bcm/bcm2708-i2s.c. Memory mapped I/O for i2s has disappeared in their 3.12 kernel.

I have patched the source and built a kernel which works on my B+ with a Cirrus Logic card.

The kernel can be downloaded from here:

https://drive.google.com/file/d/0BzIaxMH3N5O1Z0dUWjRDVktUbjQ/view?usp=sharing

File name is kernel_3_12_33_cl_mmap.tgz
Size is 16MB

md5sum: ca492de7f00cc214ccd40baf7f8288ff

The archive contains:
boot/kernel_cirrus_mmap.img          # The kernel.
lib/modules/3.12.33_CL_MMAP          # ... with many subdirectories. Kernel modules.

The archive doesn't overwrite your current kernel or modules.

To install:

• Become root: sudo -s
• Go to root directory: cd /
• Untar the archive: tar xvzf /path/to/where/you/saved/kernel_3_12_33_cl_mmap.tgz
• Add the line
    kernel=kernel_cirrus_mmap.img
  to the file /boot/config.txt
• Reboot

If it doesn't work, you can revert to your original kernel by just removing the "kernel=kernel_cirrus_mmap.img" line from /boot/config.txt

For those of you that build your own kernels, I've attached a patch file with my changes.

--

Ragnar

Thanks for the patch. I have built a new deb package for the kernel with your patch. If you like I can put it on https://blog.georgmill.de/2015/02/18/update-for-wolfson-audio-card-on-raspberry-pi/ .

Have fun.

Georg

If you like and can put it on https://blog.georgmill.de/2015/02/18/update-for-wolfson-audio-card-on-raspberry-pi/ ,too.

I have some difficulties parsing that sentence, but I think my answer is "yes"

--

Ragnar

Here you are :linux-image-3.12.33-georg_2_armhf.deb

Works OK, both Jack and the ALSA plugins.

On your website:

the Pi’s built-in audio

should be

the Wolfson/Cirrus card

or something to that effect. The Pi's builtin audio has had mmap support since 2013, but it was that patch that led me onto the right track.

--

Ragnar

Ooops, you are right. Updated the website. Thanks.

Have fun

Georg

Ooops, you are right. Updated the website. Thanks.

Have fun

Georg

Hi, thanks a lot for your help. I have installed the patch and configured everything but I did not have the time to test it.

I'll post a message with the result.

Georg, another correction for your blog:

sudo nano /etc/modules/ should be sudo nano /etc/modules

Best regards / Fernando

Thanks for that hint. Updated website some minutes ago

Best regards

Georg