[alsa-devel] [PATCH] ALSA: usb-audio: Extend DragonFly dB scale quirk to cover other variants

[Takashi Iwai]

On Fri, 23 Sep 2016 05:43:47 +0200,
Anssi Hannula wrote:
> 
> The DragonFly quirk added in 42e3121d90f4 ("ALSA: usb-audio: Add a more
> accurate volume quirk for AudioQuest DragonFly") applies a custom dB map
> on the volume control when its range is reported as 0..50 (0 .. 0.2dB).
> 
> However, there exists at least one other variant (hw v1.0c, as opposed
> to the tested v1.2) which reports a different non-sensical volume range
> (0..53) and the custom map is therefore not applied for that device.
> 
> This results in all of the volume change appearing close to 100% on
> mixer UIs that utilize the dB TLV information.
> 
> Add a fallback case where no dB TLV is reported at all if the control
> range is not 0..50 but still 0..N where N <= 1000 (3.9 dB). Also
> restrict the quirk to only apply to the volume control as there is also
> a mute control which would match the check otherwise.
> 
> Signed-off-by: Anssi Hannula <anssi.hannula at iki.fi>
> Reported-by: David W <regulars at d-dub.org.uk>
> Tested-by: David W <regulars at d-dub.org.uk>
> Cc: <stable at vger.kernel.org>

Thanks, I applied with Fixes tag.


Takashi