[alsa-devel] [PATCH - JACK PCM plugin] jack: Use boundary as hw_ptr wrap around

[Wischer, Timo (ADITG/ESB)]

Hello Takashi,

> This has nothing to do with the reported position.  If this happens,
it simply means an XRUN.  You should report the error instead.

When the ALSA buffer is full and the JACK daemon is requesting exactly the amount of samples of the buffer size
I do not see an under run here.
After such an operation the ALSA buffer is empty
but the JACK daemon has not read more samples than available.

Exactly in this case we would increment the hw_ptr += buffer_size
but this would not be recognized by the ALSA library
when we are using a wrap around of  buffer_size.


> No, the ioplug backend has to report the position from 0 to buffer_size.

I know but I think the ioplug API implementation has possibly to be changed to allow exactly such use cases
as described above.

Or do you have another idea how to report such a hw_ptr change?

Best regards

Timo Wischer

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