Re: Logitech webcam USB audio breakage during the 4.10 merge window

[Marius Cirsta]

Adding the linux-usb mailing , maybe someone from there will be able
to help with this.

On Sun, Feb 25, 2018 at 12:45 PM, Marius Cirsta <mforce2@xxxxxxxxx> wrote:
> Hi,
>
>  Thanks for your answer.
>
>  Yes, I tried reverting just that commit on top of kernel 4.15.5 and
> there was no change so I too suspect it's something from USB core
> related to the quirks that this webcam needs.
>
> Regards,
>
> Marius Cirsta,
>
> mforce2@xxxxxxxxx
>
> On Sun, Feb 25, 2018 at 11:45 AM, Takashi Iwai <tiwai@xxxxxxx> wrote:
>> On Sun, 25 Feb 2018 02:53:15 +0100,
>> Marius Cirsta wrote:
>>>
>>>  I have a problem that was previously reported here:
>>>
>>> https://www.spinics.net/lists/linux-usb/msg156999.html
>>>
>>>  It seems that with the 4.10-rc1 kernel a regression was introduced
>>> that makes my Logitech C310 microphone record a distorted ( chipmunk )
>>> sound. With the 4.9.1 kernel it works perfectly.
>>>
>>>  Immediately after I plug it into the USB port all is fine but after a
>>> few minutes this problem occurs.
>>>
>>>  Also if add this the kernel cmd line :  usbcore.autosuspend=-1  it
>>> also works fine.
>>>
>>>  One other thing that I've noticed is that if I make the sampling rate
>>> 22K it again works fine so only the 44K and 48K sampling rates have
>>> this problem but unfortunately those are the default that Chromium for
>>> instance uses ( it gets them from pulseaudio )
>>>
>>>
>>> Let me know if you need any more details or testing.
>>
>> Well it's an old topic, so I don't remember, but did you try to revert
>> the commit fd1a5059610c as already suggested?
>>
>> If it doesn't give any difference, it's not about USB-audio driver
>> side, rather likely some change in USB core.
>>
>>
>> Takashi