The Linux kernel assumes that get_endpoint(alts,0) and get_endpoint(alts,1) are eachothers feedback endpoints. To reassure that validity it will test bsynchaddress to comply with that assumption. But if the bsyncaddress is 0 (invalid), it will flag that as a wrong assumption and return an error. Fix: Skip the test if bSynchAddress is 0. Note: those with a valid bSynchAddress should have a code quirck added.
Signed-off-by: Ard van Breemen ard@kwaak.net --- sound/usb/pcm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 75b96929f76c..51a8faf25ed8 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -456,6 +456,7 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, } ep = get_endpoint(alts, 1)->bEndpointAddress; if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE && + get_endpoint(alts, 0)->bSynchAddress != 0 && ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) || (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) { dev_err(&dev->dev,