[PATCH] Fix mic sound on Jieli webcam

[Takashi Iwai]

On Tue, 15 Dec 2020 10:44:45 +0100,
Marco Giunta wrote:
> 
> Hi,
> recently I've bought a usb webcam with integrated mic:
> 
>   Jieli Technology USB PHY 2.0 (1224:2a25)
> 
> The video part works well, but the mic sound is speedups, "like
> minions" (cit.). When I connect the camera, these are the dmesg
> messages:
> 
> kernel: usb 1-8: current rate 0 is different from the runtime rate 8000
> kernel: usb 1-8: current rate 0 is different from the runtime rate 16000
> kernel: usb 1-8: current rate 0 is different from the runtime rate 44100
> kernel: usb 1-8: current rate 0 is different from the runtime rate 48000
> kernel: usb 1-8: Warning! Unlikely big volume range (=4096), cval->res
> is probably wrong.
> kernel: usb 1-8: [3] FU [Mic Capture Volume] ch = 1, val = 0/4096/1
> kernel: usbcore: registered new interface driver snd-usb-audio
> 
> and after a while, dmesg log is filled, every 5 seconds, with:
> 
> kernel: retire_capture_urb: 84 callbacks suppressed
> kernel: retire_capture_urb: 1714 callbacks suppressed
> 
> A guy reports on ArchLinux bug website the same problem
> (https://bugs.archlinux.org/task/68141?opened=12995&status%5B0%5D=)
> and provides a patch to fix the sound issue. I've applied the patch on
> kernel 5.9.13 (Fedora 33 x86_64) and now the mic works, no more
> minions voice effect. Now dmesg messages are only:
> 
> kernel: usb 1-8: Warning! Unlikely big volume range (=4096), cval->res
> is probably wrong.
> kernel: usb 1-8: [3] FU [Mic Capture Volume] ch = 1, val = 0/4096/1
> kernel: usbcore: registered new interface driver snd-usb-audio
> 
> the retire_capture_urb messages are gone.
> 
> All credits for the patch go to him but I don't know how to contact
> that guy nor I don't know if he has already contacted you, so my
> question is if you could review his patch and finally apply upstream.
> 
> If you need other information or you need a tester, I'm here.

Thanks for the patch.  The still remaining warnings are about the
mixer, and your patch doesn't touch about it.  You may apply the
similar change in volume_control_quirks() like other webcams.

And now about the patch:

> --- a/sound/usb/format.c    2020-10-01 18:36:35.000000000 +0300
> +++ b/sound/usb/format.c    2020-10-04 02:10:21.678685952 +0300
> @@ -217,6 +217,21 @@
>                  (chip->usb_id == USB_ID(0x041e, 0x4064) ||
>                   chip->usb_id == USB_ID(0x041e, 0x4068)))
>                  rate = 8000;
> +
> +            // hack for "Jieli Technology USB PHY 2.0" webcam
> +            if (chip->usb_id == USB_ID(0x1224, 0x2a25)) {
> +                switch (rate) {
> +                case 8000:
> +                    fp->datainterval += 4;
> +                    break;
> +                case 16000:
> +                    fp->datainterval += 3;
> +                    break;
> +                default:
> +                    fp->datainterval += 1;
> +                    break;
> +                }
> +            }

Modifying datainterval at this point doesn't look intuitive.
What's the original datainterval value for those altsettings?
The value is retrieved in snd_usb_parse_datainterval() in helper.c,
and if any, the correction there would be more sensible.


>              fp->rate_table[fp->nr_rates] = rate;
>              if (!fp->rate_min || rate < fp->rate_min)
> --- a/sound/usb/endpoint.c    2020-10-01 18:36:35.000000000 +0300
> +++ b/sound/usb/endpoint.c    2020-10-04 02:09:09.471978982 +0300
> @@ -882,6 +882,8 @@
>      if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
>          packs_per_ms = 8 >> ep->datainterval;
>          max_packs_per_urb = MAX_PACKS_HS;
> +        if (!packs_per_ms)
> +            packs_per_ms = 1;

This rather indicates that the datainterval is somehow wrong.

>      } else {
>          packs_per_ms = 1;
>          max_packs_per_urb = MAX_PACKS;
> --- a/sound/usb/quirks.c    2020-10-01 18:36:35.000000000 +0300
> +++ b/sound/usb/quirks.c    2020-10-04 02:14:04.532196519 +0300
> @@ -1516,6 +1516,7 @@
>      case USB_ID(0x1901, 0x0191): /* GE B850V3 CP2114 audio interface */
>      case USB_ID(0x21b4, 0x0081): /* AudioQuest DragonFly */
>      case USB_ID(0x2912, 0x30c8): /* Audioengine D1 */
> +    case USB_ID(0x1224, 0x2a25): /* Jieli Technology USB PHY 2.0 */
>          return true;
>      }

This looks fine.


thanks,

Takashi