Comment 26 for bug 1200925

In
http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/usb/mixer.c
I think your code-piece might be set better some lines above (807-905) in the section
/* volume control quirks */
static void volume_control_quirks(struct usb_mixer_elem_info *cval,
      struct snd_kcontrol *kctl)
{

...

case USB_ID(0x0d8c, 0x6):
   if (!strcmp(kctl->id.name, "Speaker Playback Volume")) {

  cval->min = ????
  cval->max = ????
  cval->res = ??? /* Maybe this is also needed */

  }
  break;

...

}

Where we don't need to know the dB's. I hope that's correct.

Or why did you choose this section?