[alsa-devel] snd-usb endpoint rework

[Aurélien Leblond]

> On 20.05.2012 16:13, Aurélien Leblond wrote:
>>> Hello everyone,
>>>
>>> I compiled today the Kernel 3.4.0-rc7 from the git and used this git
>>> to add the FTU support:
>>> git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git
>>>
>>> Unfortunately, all my USB sound card simply stopped working.
>>>
>>> The FTU doesn't produce any sound, nor through Alsa or Jack.
>>> I tried playing a simple song through mplayer and nothing. I double
>>> checked the mixer, all volumes are set as they should.
>>> I checked dmesg, no error that could help.
>>> I'm running Ubuntu, and the only thing I can hear is the welcoming
>>> sound of ubuntu being cut-off almost instantly.
>>>
>>> I tested my Edirol UA-25Ex, it is working all ok.
>>
>> Correction, the UA-25Ex doesn't work either.
>> The sound dies out after a few minutes being used.
>
> Odd. I did just that - built a kernel from Takashi's master branch - and
> cannot reproduce the effect you're seeing. I'm testing with both the FTU
> and a NI Traktor Audio 6 (which is a class compliant device) and both
> stream reliable.
>
> Are you totally sure that your hardware setup is ok? Did you change the
> USB cables or anything? Does running an older kernel, while leaving
> everthing else the same, solve the problem?

Yes, I checked running the standard Ubuntu Kernel, and the FTU/UA25-Ex
are running ok.
But it is a 3.2 Kernel, so the stream logic is not available.

Yesterday, I compiled alsa-driver from the alsa-driver.git and
alsa-kmirror.git (I'm actually not sure what is the difference between
this gits and the one from Takashi) and installed it on the kernel 3.2
coming with Ubuntu.
I get the exact same results:
- the FTU doesn't produce any sound BUT the Ubuntu welcome one.
Although the mixers are ok, I'm starting to wonder if they might still
be muted.
(on that note, the "internal" sound of the FTU is ok, I can play my
guitar plugged on the soundcard and hear it properly).
- I haven't tested the UA-25Ex with that setup, I'll try that this evening.

>> When the sound dies out, dmesg prints:
>>
>> [  550.114621] urb status -32
>> [  551.601237] urb status -32
>> [  551.681206] urb status -32
>> [  553.563336] urb status -32
>> [  565.588044] urb status -32
>> [  566.786965] urb status -32
>> [  625.130221] cannot submit urb 0, error -28: not enough bandwidth
>>
>> If there is any other info I can provide, let me know,
>
> Can you provide more context of the logs?

I'll provide a fuller log this evening.

Regards,
Aurélien