[alsa-devel] usb 1-2: 1:1: cannot set freq 44100 to ep 0x81 and potential fix

[Joakim Tjernlund]

On Sun, 2017-08-20 at 15:14 +0200, Joakim Tjernlund wrote:
> I have two USB headsets (Logitech Inc Logitech Stereo H650e and
> Jabra Jabra UC VOICE 550a) who both causes lots of:
> 
>     usb 1-2: 1:1: cannot set freq 44100 to ep 0x81
> 
> errors when using them for pidgin audio chats. The actual freq
> varies though.
> 
> I found that adding a small delay here:
>  diff -u sound/usb/clock.c.org  sound/usb/clock.c 
> --- sound/usb/clock.c.org	2017-08-18 14:38:05.597977669 +0200
> +++ sound/usb/clock.c	2017-08-18 14:20:14.653661513 +0200
> @@ -304,6 +304,7 @@
>  			iface, fmt->altsetting, rate, ep);
>  		return err;
>  	}
> +        msleep(1);
>  
>  	/* Don't check the sample rate for devices which we know don't
>  	 * support reading */
> 
> it seems one cannot do these settings too fast
> Ant better idea for a fix? kernel 4.9.44
> 
>  Jocke
> 
> PS.
>    When starting a chat with pidgin-sipe, I see the same sample rate
> freq setting twice, not sure where that comes from.
>  

I found snd_usb_ctl_msg_quirk() and if I add the same logic as
for Zoom R16/24:
+
+       /* Logitech H650e needs a tiny delay here, otherwise requests like
+        * get/set frequency return as failed despite actually succeeding.
+        */
+       if (chip->usb_id == USB_ID(0x046D, 0x0A46) &&
+           (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
+               mdelay(1);
+
+       /* Jambra 550a needs a tiny delay here, otherwise requests like
+        * get/set frequency return as failed despite actually succeeding.
+        */
+       if (chip->usb_id == USB_ID(0x0B0E, 0x0349) &&
+           (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
+               mdelay(1);

it works again. Is the above an acceptable patch ?

 Jocke