Commit 1b34121d authored by Ard van Breemen's avatar Ard van Breemen Committed by Takashi Iwai
Browse files

ALSA: usb-audio: Skip bSynchAddress endpoint check if it is invalid 



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: default avatarArd van Breemen <ard@kwaak.net>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent f7f53018

sound/usb/pcm.c

+1 −0
Original line number Diff line number Diff line
@@ -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,