[PATCH] ALSA: usb-audio: Fix missing sample-rate control for PreSonus AudioBox USB

[PATCH] ALSA: usb-audio: Fix missing sample-rate control for PreSonus AudioBox USB

[Thomas Nemer]

The fixed audio formats for the PreSonus AudioBox USB declare
.attributes = 0, dropping UAC_EP_CS_ATTR_SAMPLE_RATE that the device
advertises in its class-specific endpoint descriptors (EP_GENERAL
bmAttributes 0x01 on both EP 0x01 and EP 0x82).

As a result set_sample_rate_v1() bails out and the kernel never sends
the UAC1 SET_CUR SAMPLING_FREQ request, leaving the device on its
power-on default clock. Playback and capture then run distorted
whenever the stream rate differs from that default. The device keeps
the last rate set by a host as long as it stays powered, which made the
regression look intermittent (e.g. it disappears after the device was
initialized by a host running a kernel without this quirk entry).

Restore the sample-rate attribute on both streams.

Fixes: 34fe4a9df247 ("ALSA: usb-audio: Add quirk for PreSonus AudioBox USB")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Nemer <thomas.nemer@fortytwo.fr>
---
 sound/usb/quirks-table.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 2da8cbe3e6..6343a50fb2 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2911,7 +2911,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 					.iface = 2,
 					.altsetting = 1,
 					.altset_idx = 1,
-					.attributes = 0,
+					.attributes = UAC_EP_CS_ATTR_SAMPLE_RATE,
 					.endpoint = 0x01,
 					.ep_attr = USB_ENDPOINT_XFER_ISOC,
 					.rates = SNDRV_PCM_RATE_44100 |
@@ -2932,7 +2932,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 					.iface = 3,
 					.altsetting = 1,
 					.altset_idx = 1,
-					.attributes = 0,
+					.attributes = UAC_EP_CS_ATTR_SAMPLE_RATE,
 					.endpoint = 0x82,
 					.ep_attr = USB_ENDPOINT_XFER_ISOC,
 					.rates = SNDRV_PCM_RATE_44100 |
-- 
2.56.0

Re: [PATCH] ALSA: usb-audio: Fix missing sample-rate control for PreSonus AudioBox USB

[Takashi Iwai]

On Sun, 18 Oct 2026 13:15:19 +0200,
Thomas Nemer wrote:
> 
> The fixed audio formats for the PreSonus AudioBox USB declare
> .attributes = 0, dropping UAC_EP_CS_ATTR_SAMPLE_RATE that the device
> advertises in its class-specific endpoint descriptors (EP_GENERAL
> bmAttributes 0x01 on both EP 0x01 and EP 0x82).
> 
> As a result set_sample_rate_v1() bails out and the kernel never sends
> the UAC1 SET_CUR SAMPLING_FREQ request, leaving the device on its
> power-on default clock. Playback and capture then run distorted
> whenever the stream rate differs from that default. The device keeps
> the last rate set by a host as long as it stays powered, which made the
> regression look intermittent (e.g. it disappears after the device was
> initialized by a host running a kernel without this quirk entry).
> 
> Restore the sample-rate attribute on both streams.
> 
> Fixes: 34fe4a9df247 ("ALSA: usb-audio: Add quirk for PreSonus AudioBox USB")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thomas Nemer <thomas.nemer@fortytwo.fr>

Applied now.  Thanks.


Takashi