Re: Regression in kernel 3.19-rc5 for usb2 scarlett 18i20

[Chris J Arges <chris.j.arges@canonical.com>]

On 01/26/2015 07:28 AM, Guido Aulisi wrote:
> I will ASAP, now I'm not at home.
> IMHO I think this is something about usb than the mixer,
> because I didn't use it, I only noticed the xruns even without playing audio.
> I didn't try 3.18, because it isn't shipped with fedora yet.
> 
> Ciao
> 
> 2015-01-26 14:04 GMT+01:00 Takashi Iwai <tiwai@suse.de>:
>> At Sun, 25 Jan 2015 12:42:22 +0100,
>> Guido Aulisi wrote:
>>>
>>> Hi,
>>> I noticed a regression in 3.19-rc5 kernel (as shipped by fedora rawhide)
>>> with usb2 focusrite scarlett 18i20.
>>> I get a lot of xruns with jack, even at 1024 frame buffer and 2 periods.
>>> In 3.17.8 it works quite well without xruns at the same settings.
>>>

Guido, Takashi,

I tried to reproduce this and failed on my Scarlett 18i8 (I don't have
any other hardware).

I've just tested Ubuntu's 3.18.2 and daily mainline 3.19-r5 as follows:
1) Setup Scarlett 18i8 w/ jack (RT, 1024 frames/period, sample rate 48k,
periods/buffer 2).
2) Launch Ardour3 and create/arm 8 tracks
3) Hit record

Using this I was unable to see any XRuns even when using Scarlett's
mixer with alsamixer in the background on 3.19.

Let me know more details.
Thanks,
--chris j arges


>>> I use a fedora 20 (64bit) laptop with 8GB ram,  I only installed the
>>> rawhide kernel to try the new included scarlett mixer, no other software
>>> components changed.
>>>
>>> I can try to do some other test, but compiling the kernel on this laptop
>>> is time consuming.
>>>
>>> Thanks
>>> Guido
>>
>> Looks like a regression in the recent rework for Scarlett devices.
>> Chris, do you have any clue?
>>
>> In anyway, Guido, could you give lsusb -v output (for the relevant
>> part)?
>>
>>
>> thanks,
>>
>> Takashi
>