[alsa-devel] [PATCH 4/5] ALSA: usb-audio: stop both data and sync endpoints asynchronously

[Takashi Iwai]

As we are stopping the endpoints asynchronously now, it's better to
trigger the stop of both data and sync endpoints and wait for pending
stopping operations, instead of the sequential trigger-and-wait
procedure.

So the wait argument in snd_usb_endpoint_stop() is dropped, and it's
expected that the caller synchronizes explicitly by calling
snd_usb_endpoint_sync_pending_stop().  (Actually there is only one
place calling this, so it was safe to change.)

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/usb/endpoint.c | 11 +++++------
 sound/usb/endpoint.h |  2 +-
 sound/usb/pcm.c      |  9 +++++++--
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 6db2143..f487d26 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -896,8 +896,11 @@ __error:
  * actually be deactivated.
  *
  * Must be balanced to calls of snd_usb_endpoint_start().
+ *
+ * The caller needs to synchronize the pending stop operation via
+ * snd_usb_endpoint_sync_pending_stop().
  */
-void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool wait)
+void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
 {
 	if (!ep)
 		return;
@@ -911,11 +914,7 @@ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool wait)
 		ep->sync_slave = NULL;
 		ep->retire_data_urb = NULL;
 		ep->prepare_data_urb = NULL;
-
-		if (wait)
-			wait_clear_urbs(ep);
-		else
-			set_bit(EP_FLAG_STOPPING, &ep->flags);
+		set_bit(EP_FLAG_STOPPING, &ep->flags);
 	}
 }
 
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index f1e451d..447902d 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -17,7 +17,7 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
 				struct snd_usb_endpoint *sync_ep);
 
 int  snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep);
-void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool wait);
+void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep);
 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep);
 int  snd_usb_endpoint_activate(struct snd_usb_endpoint *ep);
 int  snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep);
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index d90604a..4750d3d 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -266,10 +266,15 @@ static int start_endpoints(struct snd_usb_substream *subs, bool can_sleep)
 static void stop_endpoints(struct snd_usb_substream *subs, bool wait)
 {
 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
-		snd_usb_endpoint_stop(subs->sync_endpoint, wait);
+		snd_usb_endpoint_stop(subs->sync_endpoint);
 
 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
-		snd_usb_endpoint_stop(subs->data_endpoint, wait);
+		snd_usb_endpoint_stop(subs->data_endpoint);
+
+	if (wait) {
+		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
+		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
+	}
 }
 
 static int deactivate_endpoints(struct snd_usb_substream *subs)
-- 
1.8.0