From 6610b57ed85ebe1fdc98a388e8a7984fc59d3bb4 Mon Sep 17 00:00:00 2001 From: Ard van Breemen Date: Fri, 2 Aug 2019 13:52:14 +0200 Subject: [PATCH] ALSA: usb-audio: Skip bSynchAddress endpoint check if it is invalid [ Upstream commit 1b34121d9f26d272b0b2334209af6b6fc82d4bf1 ] 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 Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/usb/pcm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b1a1eb1f65aa..ff38fca1781b 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -470,6 +470,7 @@ 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, -- 2.20.1