[alsa-devel] issues with usb-audio and maudio quattro

Takashi Iwai tiwai at suse.de
Sun Dec 8 10:21:20 CET 2013

At Sun, 8 Dec 2013 01:47:19 +1100 (EST),
Patrick Shirkey wrote:
> Hi,
> It seems that some changes were made to the usb-audio driver over the
> years that have resulted in partially broken  behaviour with maudio
> quattro.
> We have run some tests on two different devices with different machines
> and found the following items:
> 1: There are no longer three pcm devices - this breaks previously working
> asoundrc files
> 2: pcm0 and pcm1 have different behaviours - this results in audio input
> working for pcm0 but white noise in pcm1 (probably due to endianess le vs
> be)
> 3: We can record 4 tracks with arecord. Tracks 1/2 have audio and track
> 3/4 have white noise
> 4: We can no longer run 4 playback tracks in JACK2 as it complains about
> the ports not matching (this might be a seperate issue with JACK2 and
> route/plug configs for multichannel devices but that would probably affect
> the delta 10/10, RME Hammerfall or other multichannel devices too.)
> jackd: ../common/JackGraphManager.cpp:44: void
> Jack::JackGraphManager::AssertPort(jack_port_id_t): Assertion `port_index
> < fPortMax' failed.
> So the main question is who made the decision to drop/consolidate the
> third pcm and break previously working asoundrc files?
> There must be a good reason in which case maybe we can get things working
> again relatively easily?

I don't know of such intentional breakage.  Bisection please.


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