Is something using DMA channel 0?

[Florian Meier]

Hi Philip,
I faced some strange effects with the DMA channel 0, too. It seems to
have a special functionality, but I skipped the investigation, because I
found other channels that do the job. Are the other channels working ok?

By the way: What is your goal? If you only want to have I2S support you
can use this kernel driver:
http://blog.koalo.de/2013/05/i2s-support-for-raspberry-pi.html

Greetings,
Florian

On 07.11.2013 05:57, Philip Ashmore wrote:
> Hi there.
> 
> Please forgive me in advance if I'm posting this question on the wrong list.
> 
> I wrote a C++ library to control the Bcm2835 from user space:
> v3c-raspi: http://sourceforge.net/projects/v3craspi/
> 
> But it appears that something writes to the DMA channel 0 control
> register at random intervals - I managed to get the i2s example running
> for 5 seconds before the problem occurred. Other times it happens almost
> immediately.
> 
> I posted this bug originally:
> 
> Is something using dma channel 0?
> https://bugs.launchpad.net/raspbian/+bug/1231791
> 
> Then I found someone else who wanted to do something like it:
> 
> How fast is GPIO+DMA? Multi I2S input
> http://raspberrypi.stackexchange.com/questions/9646/how-fast-is-gpiodma-multi-i2s-input/10287#10287
> 
> But no responses to either regarding my issue.
> 
> Is this the right place to post this question?
> 
> Regards,
> Philip Ashmore
> 
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