[75/93] ALSA: usb-audio - Avoid Oops after disconnect

2.6.32-stable review patch.  If anyone has any objections, please let us know.

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

From: Takashi Iwai <tiwai@suse.de>

commit 78b8d5d2ee280c463908fd75f3bdf246bcb6ac8d upstream.

As the release of substreams may be done asynchronously from the
disconnection, close callback needs to check the shutdown flag before
actually accessing the usb interface.

Reference: Novell bnc#505027
	http://bugzilla.novell.com/show_bug.cgi?id=565027

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 sound/usb/usbaudio.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1936,7 +1936,7 @@ static int snd_usb_pcm_close(struct snd_
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_usb_substream *subs = &as->substream[direction];
 
-	if (subs->interface >= 0) {
+	if (!as->chip->shutdown && subs->interface >= 0) {
 		usb_set_interface(subs->dev, subs->interface, 0);
 		subs->interface = -1;
 	}