ALSA: usb-audio: Fix runtime PM unbalance
authorTakashi Iwai <tiwai@suse.de>
Wed, 19 Aug 2015 05:20:14 +0000 (07:20 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 13 Sep 2015 16:07:46 +0000 (09:07 -0700)
commit 9003ebb13f61e8c78a641e0dda7775183ada0625 upstream.

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')
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/usb/card.c

index 1fab977..0450593 100644 (file)
@@ -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);