[PATCH] ALSA: usb-audio fix uac2 clock source

[PATCH] ALSA: usb-audio fix uac2 clock source

[René Rebe]

Since 8b3a087f7f65 ("ALSA: usb-audio: Unify virtual type units type to
UAC3 values") usb-audio is using UAC3_CLOCK_SOURCE instead of
bDescriptorSubtype, later refactored with e0ccdef9265 ("ALSA: usb-audio:
Clean up check_input_term()") into parse_term_uac2_clock_source().

This breaks the clock source selection for at least my
1397:0003 BEHRINGER International GmbH FCA610 Pro.

Fix by using UAC2_CLOCK_SOURCE in parse_term_uac2_clock_source().

Fixes: 8b3a087f7f65 ("ALSA: usb-audio: Unify virtual type units type to UAC3 values")
Signed-off-by: René Rebe <rene@exactco.de>
---
Tested and shipped since 2022-07-24 in T2/Linux.
---
 sound/usb/mixer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 72b900505d2c..3af71d42b9b9 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -921,7 +921,7 @@ static int parse_term_uac2_clock_source(struct mixer_build *state,
 {
 	struct uac_clock_source_descriptor *d = p1;
 
-	term->type = UAC3_CLOCK_SOURCE << 16; /* virtual type */
+	term->type = UAC2_CLOCK_SOURCE << 16; /* virtual type */
 	term->id = id;
 	term->name = d->iClockSource;
 	return 0;
-- 
2.46.0

-- 
René Rebe, ExactCODE GmbH, Berlin, Germany
https://exactco.de • https://t2linux.com • https://patreon.com/renerebe

Re: [PATCH] ALSA: usb-audio fix uac2 clock source

[Takashi Iwai]

On Tue, 25 Nov 2025 15:41:49 +0100,
René Rebe wrote:
> 
> Since 8b3a087f7f65 ("ALSA: usb-audio: Unify virtual type units type to
> UAC3 values") usb-audio is using UAC3_CLOCK_SOURCE instead of
> bDescriptorSubtype, later refactored with e0ccdef9265 ("ALSA: usb-audio:
> Clean up check_input_term()") into parse_term_uac2_clock_source().
> 
> This breaks the clock source selection for at least my
> 1397:0003 BEHRINGER International GmbH FCA610 Pro.
> 
> Fix by using UAC2_CLOCK_SOURCE in parse_term_uac2_clock_source().
> 
> Fixes: 8b3a087f7f65 ("ALSA: usb-audio: Unify virtual type units type to UAC3 values")
> Signed-off-by: René Rebe <rene@exactco.de>
> ---
> Tested and shipped since 2022-07-24 in T2/Linux.

Applied now.  Thanks.


Takashi