Commit 988cc175 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usb-audio: Fix implicit sync clearance at stopping stream 



The recent endpoint management change for implicit feedback mode added
a clearance of ep->sync_sink (formerly ep->sync_slave) pointer at
snd_usb_endpoint_stop() to assure no leftover for the feedback from
the already stopped capture stream.  This turned out to cause a
regression, however, when full-duplex streams were running and only a
capture was stopped.  Because of the above clearance of ep->sync_sink
pointer, no more feedback is done, hence the playback will stall.

This patch fixes the ep->sync_sink clearance to be done only after all
endpoints are released, for addressing the regression.

Reported-and-tested-by: default avatarLucas Endres <jaffa225man@gmail.com>
Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210426063349.18601-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 316791b5

sound/usb/endpoint.c

+4 −4
Original line number Diff line number Diff line
@@ -1443,12 +1443,12 @@ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep) 
	if (snd_BUG_ON(!atomic_read(&ep->running)))

		return;



	if (!atomic_dec_return(&ep->running)) {

		if (ep->sync_source)

			WRITE_ONCE(ep->sync_source->sync_sink, NULL);



	if (!atomic_dec_return(&ep->running))

		stop_urbs(ep, false);

	}

}



/**

 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint