4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ioan-Adrian Ratiu <a...@adirat.com>


[ 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 <a...@adirat.com>
Signed-off-by: Takashi Iwai <ti...@suse.de>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 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 */


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