[alsa-devel] M-Audio FastTrack C400

Felix Homann linuxaudio at showlabor.de
Sat May 5 09:05:35 CEST 2012

Hi again,

2012/5/5 Chris Cavey <chris-alsa at rauros.net>:
> No change.

Hmm, do you still get this message:

   ALSA mixer.c:352 cannot get ctl value: req = 0x83, wValue = 0x101,
wIndex = 0x4001, type = 4
   ALSA mixer.c:877 64:1: cannot get min/max values for control 1 (id 64)

If so, can you please look at mixer.c 352 if line 352 corresponds to
get_ctl_value_v2? (My line numbers are a bit off compared to yours it
seems). Can you send some Ci lines from usbmon from before the
mesasage appears.

>  According to usbmon looks like no matter what channel I adjust,
> the clock ctl is always being adjusted as if the wrong wIndex gets selected.
> The clock wIndex is 0x8001 but the mixer volume is 0x4001. The wValue looks
> correct (first mixer, according to my docs, should be 0x0100).

That's strange. Can you try if your "return 0" instead of "break" in
the device parsing is still needed now that we have a mixer quirk?
(Just a blind guess...)

> I'm going to
> trace down the rabbit hole to learn how wValue/wIndex is derived from the
> mixer controls.

Just compare with the FTUs controls.

> I'll keep tinkering. At some point I should probably just buy you a C400,
> probably easier.

Have you thought about switching to a MOTU or RME device? Maybe we
should work on these ;-)

Kind regards,


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