Re: [Alsa-user] popping noise when switching tracks

[B. Z. <bb....@fr...>]

On 05/17/2013 04:03 PM, B. Zhang wrote:
> On 05/17/2013 03:04 PM, Torstein Hegge wrote:
>> On Fri, May 17, 2013 at 09:16:49 +0200, B. Zhang wrote:
>>> I have two alsa-info output for kernel 3.1 and 3.9. Attached.
>>> A diff show me :
>>> =======
>>>    !!Module: snd_usb_audio
>>> -    async_unlink : Y
>>> ===========
>>> I found there was a change https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/sound/usb/card.c?id=20d32022a8d8639a33d0e429f2d3c51b527ea362
>>> after kernel 3.4
>>>
>>> How you think about this ?
>> That isn't related to the pops you are hearing, the commit just removes
>> a module parameter, and the module parameter was set to the default
>> value.
> Yes ! I just made two tests.
> - kernel 3.9.2 + "async_unlink", the problem still exists
> - kernel 3.5.7, no "pops" noise,  and I see "feedback format = 8.16", so
> the noises are not caused by it.
>> There is quite a bit of changes both in sound/usb and drivers/usb
>> between 3.4 and 3.9. You could try to test with a 3.5 kernel and a 3.8
>> kernel to narrow down where the problem is coming from. Testing with 3.6
>> and 3.7 would require that you apply the fix for the "atomic DMA
>> coherent pool is too small" issue.
> I'll try 3.6 (and 3.7). Maybe it is caused by a drivers/usb change in
> kernel 3.6.

I tried 3.6.11 and 3.7.10.
3.6.11 OK.
3.7.10 has this noise problem ( buffers management problem? ) with my 
USB interface.
It seems to me that there was a big ALSA updatefrom 3.6 to 3.7.

Regards,
Bin