From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C600C433E6 for ; Mon, 15 Mar 2021 14:11:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E39EB64E81 for ; Mon, 15 Mar 2021 14:11:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235718AbhCOOLL (ORCPT ); Mon, 15 Mar 2021 10:11:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:37500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231460AbhCON6W (ORCPT ); Mon, 15 Mar 2021 09:58:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ED17A64F09; Mon, 15 Mar 2021 13:58:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816700; bh=qJ6QJ2Eug/caeEXe+T5TRyjcVE0TEXz068KRnTtgibc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yqr5/NxIyCIVa258IcLAbK/UIBkq+q7lik8EMYyi2a8V2m+C7wKrkrVDfqS2wK63x Cl2RdfbKcxXpm1zhMi7QlHyK2AER1eHlLastmKuLeUIuEb97Ti89okE9cXlqapyCgW vYaSpt5pGoD+q+b4u7z6AhEnhyxyd1SdNdESzMZk= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxim Mikityanskiy , Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH 5.4 055/168] media: usbtv: Fix deadlock on suspend Date: Mon, 15 Mar 2021 14:54:47 +0100 Message-Id: <20210315135552.166965723@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135550.333963635@linuxfoundation.org> References: <20210315135550.333963635@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Maxim Mikityanskiy 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 --- 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 @@ -399,7 +399,7 @@ 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; } }