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From:   Marius Cirsta <mforce2@gmail.com>
Date:   Sun, 25 Feb 2018 12:45:51 +0200
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Subject: Re: Logitech webcam USB audio breakage during the 4.10 merge window
To:     Takashi Iwai <tiwai@suse.de>
Cc:     linux-kernel@vger.kernel.org, Gabriel C <nix.or.die@gmail.com>,
        gregkh@linuxfoundation.org
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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@gmail.com

On Sun, Feb 25, 2018 at 11:45 AM, Takashi Iwai <tiwai@suse.de> 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