From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
From: Maxim Mikityanskiy <maxtram95@xxxxxxxxx>
commit 8a7e27fd5cd696ba564a3f62cedef7269cfd0723 upstream.
usbtv doesn't support power management, so on system suspend the
.disconnect callback of the driver is called. The teardown sequence
includes a call to snd_card_free. Its implementation waits until the
refcount of the sound card device drops to zero, however, if its file is
open, snd_card_file_add takes a reference, which can't be dropped during
the suspend, because the userspace processes are already frozen at this
point. snd_card_free waits for completion forever, leading to a hang on
suspend.
This commit fixes this deadlock condition by replacing snd_card_free
with snd_card_free_when_closed, that doesn't wait until all references
are released, allowing suspend to progress.
Fixes: 63ddf68de52e ("[media] usbtv: add audio support")
Signed-off-by: Maxim Mikityanskiy <maxtram95@xxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/usb/usbtv/usbtv-audio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/usb/usbtv/usbtv-audio.c
+++ b/drivers/media/usb/usbtv/usbtv-audio.c
@@ -384,7 +384,7 @@ void usbtv_audio_free(struct usbtv *usbt
cancel_work_sync(&usbtv->snd_trigger);
if (usbtv->snd && usbtv->udev) {
- snd_card_free(usbtv->snd);
+ snd_card_free_when_closed(usbtv->snd);
usbtv->snd = NULL;
}
}
