Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941065AbcKNDLx (ORCPT ); Sun, 13 Nov 2016 22:11:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46190 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754177AbcKNCF4 (ORCPT ); Sun, 13 Nov 2016 21:05:56 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Takashi Iwai" Date: Mon, 14 Nov 2016 00:14:07 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 013/152] ALSA: ctl: Stop notification after disconnection In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 35 3.2.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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: Ben Hutchings --- sound/core/control.c | 2 ++ 1 file changed, 2 insertions(+) --- a/sound/core/control.c +++ b/sound/core/control.c @@ -150,6 +150,8 @@ void snd_ctl_notify(struct snd_card *car 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++;