[alsa-devel] USB Audio device syncpipe error

Daniel Mack daniel at caiaq.de
Fri Sep 10 08:21:41 CEST 2010

On Thu, Sep 09, 2010 at 04:51:45PM -0500, 6275 kson wrote:
> Well I basically understand what is wrong.  Usbaudio is expecting the packet
> size to be 4 and the value to be encoded as 16.16 because the device is
> operating at high speed.  I made the change and my device now shows up
> properly as an output device and playback works but the feedback polling
> interval is incorrect.
> Since the feedback endpoint descriptor is not class specific I can see why
> one would expect it to be a usb 2.0 standard endpoint descriptor, however,
> that would mean I should also change my other audio streaming endpoint
> descriptors.
> Unfortunately, I'm not sure the proper way to fix this - any advice would be
> appreciated.

Hmm, I don't get your point. Why don't you just change the bInterval
field of your endpoint descriptor? Does your device work with OSX, for


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