DAC issues with XMOS usb chipset and Roon on Linux

We have a pretty thorough understanding of the issue…

  • Original bug is in the XMOS implementation…there is no controversy about this at this stage. That bug has been around for a long, long time, and likely impacts quite a few products.
  • When you combine that XMOS bug with a new enough Linux kernel, this bad behavior is exposed. This part seems to be because newer Linux kernels perform better, and this bug is timing related, so with newer Linux, the DAC is asked to process commands faster, and this trips it up because of the XMOS bug.

The second factor–i.e. that ROCK is using a newer version of Linux which performs better–is not a fault with ROCK. It is just a fact of life in a world where things keep moving forward. If the Linux kernel were broken, we would have fixed it long ago…but we’ve investigated, and it is totally compliant. This is also why ROCK is different from some other Linux stuff you may be using. We are better at keeping up to date, and flowing the latest performance improvements into our OS than some others.

I’m not sure if you’ve the homework required to make the conclusions you’re making. I’ve read the XMOS code, and the Linux code, have experimented with the timing characteristics that expose the bug, and understand it thoroughly and personally as an engineer. I also am the architect behind RAAT and ROCK and understand clearly which part of the system is responsible for what. You’re challenging the wrong guy on the technical facts :slight_smile:

If this bug were ours, we’d be all over fixing the code. That would be the best case scenario, because we would be in total control of the issue and no longer talking about it–But it isn’t ours. Of course, we are still all over it, coordinating communication with manufacturers, explaining the technicalities so they know what to do, etc, in an attempt to get this fixed for everyone.

The only thing we can’t control here is how quickly they move. If you’re concerned about a particular product, reaching out to the manufacturer can only help them understand that this is important to you.

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