From 0f174b3525a43bd51f9397394763925e0ebe7bc7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 16 Aug 2017 14:18:37 +0200 Subject: ALSA: usb-audio: Add mute TLV for playback volumes on C-Media devices C-Media devices (at least some models) mute the playback stream when volumes are set to the minimum value. But this isn't informed via TLV and the user-space, typically PulseAudio, gets confused as if it's still played in a low volume. This patch adds the new flag, min_mute, to struct usb_mixer_elem_info for indicating that the mixer element is with the minimum-mute volume. This flag is set for known C-Media devices in snd_usb_mixer_fu_apply_quirk() in turn. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196669 Cc: Signed-off-by: Takashi Iwai --- sound/usb/mixer_quirks.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'sound/usb/mixer_quirks.c') diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index e3d1dec48ee4..e1e7ce9ab217 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -1878,6 +1878,12 @@ void snd_usb_mixer_fu_apply_quirk(struct usb_mixer_interface *mixer, if (unitid == 7 && cval->control == UAC_FU_VOLUME) snd_dragonfly_quirk_db_scale(mixer, cval, kctl); break; + /* lowest playback value is muted on C-Media devices */ + case USB_ID(0x0d8c, 0x000c): + case USB_ID(0x0d8c, 0x0014): + if (strstr(kctl->id.name, "Playback")) + cval->min_mute = 1; + break; } } -- cgit v1.2.3-59-g8ed1b