ID 045e:070f Microsoft Corp. LifeChat LX-3000 Headset
has muted minimum Speaker Playback Volume, and 4 amixer steps were
observed to produce 1 actual volume step.

Apply min_mute quirk and correct res=48 -> 4*48.
Tested with the device.

Signed-off-by: Pauli Virtanen <pav@iki.fi>
---
 sound/usb/mixer.c  | 8 ++++++++
 sound/usb/quirks.c | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index ae412e651faf..6f00e0d52382 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1147,6 +1147,14 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
 		}
 		break;
 
+	case USB_ID(0x045e, 0x070f): /* MS LifeChat LX-3000 Headset */
+		if (!strcmp(kctl->id.name, "Speaker Playback Volume")) {
+			usb_audio_info(chip,
+				"set volume quirk for MS LifeChat LX-3000\n");
+			cval->res = 192;
+		}
+		break;
+
 	case USB_ID(0x0471, 0x0101):
 	case USB_ID(0x0471, 0x0104):
 	case USB_ID(0x0471, 0x0105):
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 43793a5c3f51..dac469a8d07a 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2153,6 +2153,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 	DEVICE_FLG(0x045e, 0x083c, /* MS USB Link headset */
 		   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_CTL_MSG_DELAY |
 		   QUIRK_FLAG_DISABLE_AUTOSUSPEND),
+	DEVICE_FLG(0x045e, 0x070f, /* MS LifeChat LX-3000 Headset */
+		   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
 	DEVICE_FLG(0x046d, 0x0807, /* Logitech Webcam C500 */
 		   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
 	DEVICE_FLG(0x046d, 0x0808, /* Logitech Webcam C600 */
-- 
2.51.0

On Wed, 15 Oct 2025 21:47:10 +0200,
Pauli Virtanen wrote:
> 
> ID 045e:070f Microsoft Corp. LifeChat LX-3000 Headset
> has muted minimum Speaker Playback Volume, and 4 amixer steps were
> observed to produce 1 actual volume step.
> 
> Apply min_mute quirk and correct res=48 -> 4*48.
> Tested with the device.
> 
> Signed-off-by: Pauli Virtanen <pav@iki.fi>

Thanks, applied now.


Takashi