[PATCH 3.19.y-ckt 073/102] ALSA: usb-audio: Fix runtime PM unbalance

Kamal Mostafa kamal at canonical.com
Tue Sep 22 17:52:09 UTC 2015


3.19.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

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

From: Takashi Iwai <tiwai at suse.de>

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 at nvidia.com>
Fixes: 1ee23fe07ee8 ('ALSA: usb-audio: Fix deadlocks at resuming')
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/usb/card.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1fab977..0450593 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);
-- 
1.9.1





More information about the kernel-team mailing list