From: Takashi Iwai Date: Mon, 26 Apr 2021 06:33:49 +0000 (+0200) Subject: ALSA: usb-audio: Fix implicit sync clearance at stopping stream X-Git-Tag: v5.13-rc1~87^2~22 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=988cc17552606be67a956cf8cd6ff504cfc5d643;p=thirdparty%2Fkernel%2Flinux.git 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: Lucas Endres Fixes: bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management") Cc: Link: https://lore.kernel.org/r/20210426063349.18601-1-tiwai@suse.de Signed-off-by: Takashi Iwai --- diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index f4c3d2b38abbe..014c438628262 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -1443,11 +1443,11 @@ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep) if (snd_BUG_ON(!atomic_read(&ep->running))) return; - if (ep->sync_source) - WRITE_ONCE(ep->sync_source->sync_sink, NULL); - - if (!atomic_dec_return(&ep->running)) + if (!atomic_dec_return(&ep->running)) { + if (ep->sync_source) + WRITE_ONCE(ep->sync_source->sync_sink, NULL); stop_urbs(ep, false); + } } /**