ALSA: usb-audio: Cap the packet size pre-calculations

We calculate the possible packet sizes beforehand for adaptive and
synchronous endpoints, but we didn't take care of the max frame size
for those pre-calculated values.  When a device or a bus limits the
packet size, a high sample rate or a high number of channels may lead
to the packet sizes that are larger than the given limit, which
results in an error from the USB core at submitting URBs.

As a simple workaround, just add the sanity checks of pre-calculated
packet sizes to have the upper boundary of ep->maxframesize.

Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221076
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260225085233.316306-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 73bce9712dbd6fbdbab5a8d727d519e61dd3700a..c887c2f5b25dca6b3eebd18002f5d81f989ca590 100644 (file)
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1378,6 +1378,9 @@ int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
                return -EINVAL;
        }
 
+       ep->packsize[0] = min(ep->packsize[0], ep->maxframesize);
+       ep->packsize[1] = min(ep->packsize[1], ep->maxframesize);
+
        /* calculate the frequency in 16.16 format */
        ep->freqm = ep->freqn;
        ep->freqshift = INT_MIN;