From 0c3cee57efcb1c79d62b1238c0d22afef4599247 Mon Sep 17 00:00:00 2001 From: Javier Kohen Date: Tue, 17 Nov 2009 15:36:13 +0100 Subject: ALSA: usb - Quirk to disable master volume control in PCM2702 Disable the master volume control in the PCM2702 chipset. The datasheet documents two independent channel volume controls, one master mute control and one master volume control. All controls are fully functional except for the master volume control, which returns USB stalls on all GET requests. Signed-off-by: Javier Kohen Signed-off-by: Takashi Iwai --- sound/usb/usbmixer.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c index 9efcfd08d747..c998220b99c6 100644 --- a/sound/usb/usbmixer.c +++ b/sound/usb/usbmixer.c @@ -1071,6 +1071,15 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, unsig channels = (ftr[0] - 7) / csize - 1; master_bits = snd_usb_combine_bytes(ftr + 6, csize); + /* master configuration quirks */ + switch (state->chip->usb_id) { + case USB_ID(0x08bb, 0x2702): + snd_printk(KERN_INFO + "usbmixer: master volume quirk for PCM2702 chip\n"); + /* disable non-functional volume control */ + master_bits &= ~(1 << (USB_FEATURE_VOLUME - 1)); + break; + } if (channels > 0) first_ch_bits = snd_usb_combine_bytes(ftr + 6 + csize, csize); else -- cgit v1.2.3