From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 19 Aug 2015 05:20:14 +0000 (+0200)
Subject: ALSA: usb-audio: Fix runtime PM unbalance
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9003ebb13f61e8c78a641e0dda7775183ada0625;p=linux-beck.git

ALSA: usb-audio: Fix runtime PM unbalance

The fix for deadlock in PM in commit [1ee23fe07ee8: ALSA: usb-audio:
Fix deadlocks at resuming] introduced a new check of in_pm flag.
However, the brainless patch author evaluated it in a wrong way
(logical AND instead of logical OR), thus usb_autopm_get_interface()
is wrongly called at probing, leading to unbalance of runtime PM
refcount.

This patch fixes it by correcting the logic.

Reported-by: Hans Yang <hansy@nvidia.com>
Fixes: 1ee23fe07ee8 ('ALSA: usb-audio: Fix deadlocks at resuming')
Cc: <stable@vger.kernel.org> [v3.15+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1fab9778807a..0450593980fd 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -638,7 +638,7 @@ int snd_usb_autoresume(struct snd_usb_audio *chip)
 	int err = -ENODEV;
 
 	down_read(&chip->shutdown_rwsem);
-	if (chip->probing && chip->in_pm)
+	if (chip->probing || chip->in_pm)
 		err = 0;
 	else if (!chip->shutdown)
 		err = usb_autopm_get_interface(chip->pm_intf);