This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usb-audio-test-ep_flag_running-at-urb-completion.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Aug 4 15:30:20 PDT 2017
From: Ioan-Adrian Ratiu <adi@xxxxxxxxxx>
Date: Thu, 5 Jan 2017 00:37:47 +0200
Subject: ALSA: usb-audio: test EP_FLAG_RUNNING at urb completion
From: Ioan-Adrian Ratiu <adi@xxxxxxxxxx>
[ Upstream commit 13a6c8328e6056932dc680e447d4c5e8ad9add17 ]
Testing EP_FLAG_RUNNING in snd_complete_urb() before running the completion
logic allows us to save a few cpu cycles by returning early, skipping the
pending urb in case the stream was stopped; the stop logic handles the urb
and sets the completion callbacks to NULL.
Signed-off-by: Ioan-Adrian Ratiu <adi@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/endpoint.c | 3 +++
1 file changed, 3 insertions(+)
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -384,6 +384,9 @@ static void snd_complete_urb(struct urb
if (unlikely(atomic_read(&ep->chip->shutdown)))
goto exit_clear;
+ if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+ goto exit_clear;
+
if (usb_pipeout(ep->pipe)) {
retire_outbound_urb(ep, ctx);
/* can be stopped during retire callback */
Patches currently in stable-queue which might be from adi@xxxxxxxxxx are
queue-4.4/alsa-usb-audio-test-ep_flag_running-at-urb-completion.patch