From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753403AbcHUPdy (ORCPT ); Sun, 21 Aug 2016 11:33:54 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:55640 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932679AbcHUPdu (ORCPT ); Sun, 21 Aug 2016 11:33:50 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 131/180] ALSA: ctl: Stop notification after disconnection Date: Sun, 21 Aug 2016 17:31:01 +0200 Message-Id: <1471793510-13022-132-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1471793510-13022-1-git-send-email-w@1wt.eu> References: <1471793510-13022-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Iwai commit f388cdcdd160687c6650833f286b9c89c50960ff upstream. snd_ctl_remove() has a notification for the removal event. It's superfluous when done during the device got disconnected. Although the notification itself is mostly harmless, it may potentially be harmful, and should be suppressed. Actually some components PCM may free ctl elements during the disconnect or free callbacks, thus it's no theoretical issue. This patch adds the check of card->shutdown flag for avoiding unnecessary notifications after (or during) the disconnect. Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- sound/core/control.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/core/control.c b/sound/core/control.c index 3fcead6..251bc57 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -150,6 +150,8 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask, if (snd_BUG_ON(!card || !id)) return; + if (card->shutdown) + return; read_lock(&card->ctl_files_rwlock); #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) card->mixer_oss_change_count++; -- 2.8.0.rc2.1.gbe9624a