ALSA driver does not have mmap capability ... s67_driver
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Posts: 5
Joined: Thu Feb 14, 2019 05:58

ALSA driver does not have mmap capability

Postby ccaudle » Thu Feb 14, 2019 06:34

I am not familiar yet with details of other ALSA drivers to know why this occurs, but when attempting to use the Ravenna ALSA driver with jackd (JACK audio connection kit daemon), this error occurs and the jack server will not use the Ravenna driver:

configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: mmap-based access is not possible for the capture stream of this
audio interface
ALSA: cannot configure capture channel

As jackd is one of the most critical tools for audio production on Linux this seems to be a very big oversight. A similar error occurs when attempting to use the ALSA backend of Ardour, which is the premier open-source DAW application on Linux, so it seems that the driver is not currently usable for professional or audio production use. Is this currently understood and in the process of being addressed, or is the driver only currently being used for hi-fi playback on NADAC or similar consumer devices?

Posts: 74
Joined: Wed May 29, 2002 10:02
Location: Lausanne Switzerland

Re: ALSA driver does not have mmap capability

Postby florian » Mon Mar 04, 2019 10:11

I confirm that our ALSA driver has no mmap capabilities. And this seems to be required for Jack ans some DAW. We have multiple requests for mmap support. This become the number 1 feature request.

Thanks for you feedback.