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=-13.8 required=3.0 tests=BAYES_00, 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 141B4C433E0 for ; Tue, 29 Dec 2020 08:26:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8DC322209 for ; Tue, 29 Dec 2020 08:26:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726300AbgL2I0b (ORCPT ); Tue, 29 Dec 2020 03:26:31 -0500 Received: from mx2.suse.de ([195.135.220.15]:52406 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbgL2I0a (ORCPT ); Tue, 29 Dec 2020 03:26:30 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C9768AFF0; Tue, 29 Dec 2020 08:25:48 +0000 (UTC) Date: Tue, 29 Dec 2020 09:25:48 +0100 Message-ID: From: Takashi Iwai To: Defang Bo Cc: perex@perex.cz, tiwai@suse.com, tom.ty89@gmail.com, kai.heng.feng@canonical.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ALSA:usb-audio:check urb before kill it In-Reply-To: <1609074299-3990670-1-git-send-email-bodefang@126.com> References: <1609074299-3990670-1-git-send-email-bodefang@126.com> 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 Sun, 27 Dec 2020 14:04:59 +0100, Defang Bo wrote: > > Similar to commit<124751d5e>, there should be a check for urb before kill it. > > Signed-off-by: Defang Bo usb_kill_urb() accepts the NULL urb pointer, so the NULL check in the caller side is basically superfluous. thanks, Takashi > --- > sound/usb/mixer.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c > index 81e987e..0223ef3 100644 > --- a/sound/usb/mixer.c > +++ b/sound/usb/mixer.c > @@ -3589,8 +3589,10 @@ void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) > /* stop any bus activity of a mixer */ > static void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer) > { > - usb_kill_urb(mixer->urb); > - usb_kill_urb(mixer->rc_urb); > + if (mixer->urb) > + usb_kill_urb(mixer->urb); > + if (mixer->rc_urb) > + usb_kill_urb(mixer->rc_urb); > } > > static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer) > -- > 2.7.4 >