Commit aff252a8 authored Aug 01, 2012 by Daniel Mack Committed by Takashi Iwai Aug 01, 2012

ALSA: snd-usb: fix clock source validity index



uac_clock_source_is_valid() uses the control selector value to access
the bmControls bitmap of the clock source unit. This is wrong, as
control selector values start from 1, while the bitmap uses all
available bits.

In other words, "Clock Validity Control" is stored in D3..2, not D5..4
of the clock selector unit's bmControls.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-by: Andreas Koch <andreas@akdesigninc.com>
Cc: stable@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 1f43f6c1

sound/usb/clock.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -111,7 +111,8 @@ static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
		return 0;

		/* If a clock source can't tell us whether it's valid, we assume it is */
		if (!uac2_control_is_readable(cs_desc->bmControls, UAC2_CS_CONTROL_CLOCK_VALID))
		if (!uac2_control_is_readable(cs_desc->bmControls,
		UAC2_CS_CONTROL_CLOCK_VALID - 1))
		return 1;

		err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,

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