[alsa-devel] [FT C400,RFC 0/6] M-Audio Fast Track C400

[Grant Diffey]

64samples/frame doesn't work for me ever

I'll build this patchset and test with an ftu tonight/tomorrow (yay for cup
day holiday)

Grant.


On Sun, Nov 4, 2012 at 12:40 AM, Eldad Zack <eldad at fogrefinery.com> wrote:

> Hi,
>
> The following patches adds support for the M-Audio Fast Track C400.
> I recently bought this device and I was able to get this work thanks to
> the discussion on the alsa-devel list.[1]
> Thanks everyone!
>
> This series applies against the latest mainline tree, 3.7-rc3
> (HEAD 0f89a5733a8d28174c7adeb1fdc20ac11439e766 )
>
> * First of all, everything works: mixer controls, effects control,
> playback and capture (with the correct sampling frequency set).
> Note that the device doesn't really have a master control or left/right
> pan. It's just "emulated" in the software.
> Audio in/out works good (but not good enough yet, see below).
> Playback and capture at 48KHz as well as 96KHz works fine (if you don't
> mind an xrun every 2-5 minutes). I've captured with the C400 and played
> it back on my on-board device and vice versa to make sure it gets the
> sample rate correctly.
>
> * The clock sources are still named "Unit 129" (0x81, internal) and
> "Unit 130" (0x82, SPDIF). I'll fix this later. I also plan to fix the
> channel names (i.e., instead of "AIn3", use "SPDIF In L").
>
> * I've touched one FTU mixer creation function. I'd appreciate if someone
> can test this with the FTU to make sure I didn't break something.
>
> * The last two patches are not ready to go in. Patch #5 employs a crude
> hack and misuses cmask. Patch #6 follows suit. I'd appreciate some
> hints on how to do this properly.
> (It's theoretically possible to use cmask properly, but cmasks must be
> a 64 bits type, because we have 10 input * 6 output = 60 paths).
>
> * Somewhat unrelated: I encounter latency issues. I'm not sure if it's
> just my particular hardware/drivers. I'm getting jack xruns even with
> very large buffers and low sampling frequency. Jackd is running alone,
> with almost no system activity (no X).
> With the USB 2.0 interface (ehci) I have also experienced hard lock-ups
> after a while (or almost immediately with 96KHz @ 64 bytes * 2 periods).
> Luckily I have a USB 3.0 interfaces as well (Intel xhci), which doesn't
> lock-up, but I still get xruns once every 2-5 minutes. (1000HZ kernel,
> with PREEMPT).
> Also, xruns are much less frequent when using only capture or only
> playback.
>
> Chris, do you mind testing this and see if (1) it works for you and (2)
> you see the same latency issues? Thanks for the USB captures, it really
> saved a lot of work to get this done!
>
> Cheers,
> Eldad
>
> Cc: Chris Cavey <chris-alsa at rauros.net>
> Signed-off-by: Eldad Zack <eldad at fogrefinery.com>
>
> --
>
> Eldad Zack (6):
>   usb-audio: skip UAC2 EFFECT_UNIT
>   usb-audio: parameterize FTU effect unit control
>   usb-audio: M-Audio Fast Track C400 quirks table
>   usb-audio: Fast Track C400 mixer ranges
>   usb-audio: Fast Track C400 mixer quirks
>   usb-audio: add remaining C400 controls
>
>  sound/usb/mixer.c        |   55 +++++++++++++-
>  sound/usb/mixer_quirks.c |  196
> ++++++++++++++++++++++++++++++++++++++++++++--
>  sound/usb/quirks-table.h |   71 +++++++++++++++++
>  3 files changed, 313 insertions(+), 9 deletions(-)
>
> --
> 1.7.8.6
>
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