From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Maxim Mikityanskiy maxtram95@gmail.com
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@gmail.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -398,7 +398,7 @@ 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; } }