From 897060bb6f27ed021a2700276cef68d12a76d8f7 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Sat, 27 Mar 2021 03:28:43 +0000 Subject: [PATCH] media: usbtv: Fix deadlock on suspend MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit stable inclusion from stable-5.10.24 commit c29dcb253a6a9d031eba57afaf355a2b13fe42a9 bugzilla: 51348 -------------------------------- 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman Signed-off-by: Chen Jun Acked-by:  Weilong Chen Signed-off-by: Zheng Zengkai --- drivers/media/usb/usbtv/usbtv-audio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/usb/usbtv/usbtv-audio.c b/drivers/media/usb/usbtv/usbtv-audio.c index b57e94fb1977..333bd305a4f9 100644 --- a/drivers/media/usb/usbtv/usbtv-audio.c +++ b/drivers/media/usb/usbtv/usbtv-audio.c @@ -371,7 +371,7 @@ void usbtv_audio_free(struct usbtv *usbtv) 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; } } -- GitLab