From 13fe9058ed09d5f89c28afdf971614f0c70dc9d3 Mon Sep 17 00:00:00 2001
From: Federico Cuello <fedux@fedux.com.ar>
Date: Wed, 9 May 2018 00:13:38 +0200
Subject: [PATCH] ALSA: usb: mixer: volume quirk for CM102-A+/102S+

commit 21493316a3c4598f308d5a9fa31cc74639c4caff upstream.

Currently it's not possible to set volume lower than 26% (it just mutes).

Also fixes this warning:

  Warning! Unlikely big volume range (=9472), cval->res is probably wrong.
  [13] FU [PCM Playback Volume] ch = 2, val = -9473/-1/1

, and volume works fine for full range.

Signed-off-by: Federico Cuello <fedux@fedux.com.ar>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/usb/mixer.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 89efec891e68..4d950b7c2f97 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -911,6 +911,14 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
 		}
 		break;
 
+	case USB_ID(0x0d8c, 0x0103):
+		if (!strcmp(kctl->id.name, "PCM Playback Volume")) {
+			usb_audio_info(chip,
+				 "set volume quirk for CM102-A+/102S+\n");
+			cval->min = -256;
+		}
+		break;
+
 	case USB_ID(0x0471, 0x0101):
 	case USB_ID(0x0471, 0x0104):
 	case USB_ID(0x0471, 0x0105):