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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 123CBC4338F for ; Tue, 3 Aug 2021 07:40:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF72B60F8F for ; Tue, 3 Aug 2021 07:40:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234227AbhHCHlD (ORCPT ); Tue, 3 Aug 2021 03:41:03 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:37260 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234082AbhHCHlC (ORCPT ); Tue, 3 Aug 2021 03:41:02 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id B787E2207D; Tue, 3 Aug 2021 07:40:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1627976450; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cgOa2hYCzUhkzA5o+v8md7JL/JoOvkhgxW1hqHyI39s=; b=GWdBVFHtdj6usslVn+rJCIORJC6ccdbjbaeT2m22sp47kU+JZZe8/Dx+2/rMPLdFkHt3MA UuIzkhEnTOkudhwkxdsKVcbM9uFp0nl+UCTbfQbjzrxkqf46lxzN1CcoAgocoqC+eMTafM /pYpsGZRTbpELwKLPAMWFwwPkl+YPwk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1627976450; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cgOa2hYCzUhkzA5o+v8md7JL/JoOvkhgxW1hqHyI39s=; b=uIXpxfNLscdavhW0rkVpJ8hFabhjX7mE/eJ/z2P5b0Fzgxjv8vG2xF85S5qnSPsCdEKPxD 8UTVCMIBzpL4KPAw== Received: from alsa1.suse.de (alsa1.suse.de [10.160.4.42]) by relay2.suse.de (Postfix) with ESMTP id 8F119A3BC9; Tue, 3 Aug 2021 07:40:50 +0000 (UTC) Date: Tue, 03 Aug 2021 09:40:50 +0200 Message-ID: From: Takashi Iwai To: Salah Triki Cc: Jaroslav Kysela , Takashi Iwai , Pavel Skripkin , Kai-Heng Feng , Mark Brown , Joe Perches , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sound: usb: get lock before calling usb_enable_autosuspend() In-Reply-To: <20210802225339.GA1461793@pc> References: <20210802225339.GA1461793@pc> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 03 Aug 2021 00:53:39 +0200, Salah Triki wrote: > > Based on the documentation of usb_enable_autosuspend(), the > caller must hold udev's device lock. The device lock is already held in the caller side (in the driver core), hence this change will lead to a deadlock. thanks, Takashi > > Signed-off-by: Salah Triki > --- > sound/usb/card.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/sound/usb/card.c b/sound/usb/card.c > index 2f6a62416c05..9290ba0acd5f 100644 > --- a/sound/usb/card.c > +++ b/sound/usb/card.c > @@ -907,8 +907,13 @@ static void usb_audio_disconnect(struct usb_interface *intf) > } > } > > - if (chip->quirk_type & QUIRK_SETUP_DISABLE_AUTOSUSPEND) > - usb_enable_autosuspend(interface_to_usbdev(intf)); > + if (chip->quirk_type & QUIRK_SETUP_DISABLE_AUTOSUSPEND) { > + struct usb_device *udev = interface_to_usbdev(intf); > + > + usb_lock_device(udev); > + usb_enable_autosuspend(udev); > + usb_unlock_device(udev); > + } > > chip->num_interfaces--; > if (chip->num_interfaces <= 0) { > -- > 2.25.1 >