From: Mike Lockwood <lockwood@google.com>
Date: Thu, 29 Jan 2015 21:37:06 +0000 (-0800)
Subject: USB: gadget: midi: Fix deadlock unbinding driver while it is in use
X-Git-Tag: firefly_0821_release~4090^2~42
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=261230ce54cfc119efe643fc1d128e431d1678d3;p=firefly-linux-kernel-4.4.55.git

USB: gadget: midi: Fix deadlock unbinding driver while it is in use

Using snd_card_free_when_closed rather than snd_card_free in f_midi_unbind
makes it safe to disable the driver while a userspace client has the
ALSA device open.

Change-Id: Ibc40c01e7b1ce90fc61d3ea654b4816fadfc7ffd
Signed-off-by: Mike Lockwood <lockwood@google.com>
---

diff --git a/drivers/usb/gadget/f_midi.c b/drivers/usb/gadget/f_midi.c
index 263e721c2694..b91f519776ce 100644
--- a/drivers/usb/gadget/f_midi.c
+++ b/drivers/usb/gadget/f_midi.c
@@ -409,7 +409,7 @@ static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
 	card = midi->card;
 	midi->card = NULL;
 	if (card)
-		snd_card_free(card);
+		snd_card_free_when_closed(card);
 
 	kfree(midi->id);
 	midi->id = NULL;