From patchwork Sun Jan 25 13:34:29 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Clemens Ladisch X-Patchwork-Id: 5701481 Return-Path: X-Original-To: patchwork-alsa-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8D1AFC058D for ; Sun, 25 Jan 2015 13:34:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AEC04201EC for ; Sun, 25 Jan 2015 13:34:50 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.kernel.org (Postfix) with ESMTP id B3930201E4 for ; Sun, 25 Jan 2015 13:34:48 +0000 (UTC) Received: by alsa0.perex.cz (Postfix, from userid 1000) id D40EB260461; Sun, 25 Jan 2015 14:34:47 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from alsa0.perex.cz (localhost [IPv6:::1]) by alsa0.perex.cz (Postfix) with ESMTP id AD4D5260447; Sun, 25 Jan 2015 14:34:39 +0100 (CET) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id 7B6E9260444; Sun, 25 Jan 2015 14:34:38 +0100 (CET) Received: from dehamd003.servertools24.de (dehamd003.servertools24.de [31.47.254.18]) by alsa0.perex.cz (Postfix) with ESMTP id 807F6260438 for ; Sun, 25 Jan 2015 14:34:31 +0100 (CET) Received: from [192.168.42.120] (tmo-099-53.customers.d1-online.com [80.187.99.53]) by dehamd003.servertools24.de (Postfix) with ESMTPSA id 92759F804E; Sun, 25 Jan 2015 14:29:42 +0100 (CET) Message-ID: <54C4F0E5.8030205@ladisch.de> Date: Sun, 25 Jan 2015 14:34:29 +0100 From: Clemens Ladisch User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Takashi Iwai References: <54C4F0A1.2000907@ladisch.de> In-Reply-To: <54C4F0A1.2000907@ladisch.de> X-PPP-Message-ID: <20150125132942.899711.17244@dehamd003.servertools24.de> X-PPP-Vhost: ladisch.de Cc: alsa-devel@alsa-project.org Subject: [alsa-devel] [PATCH 1/6] ALSA: seq-dummy: remove deadlock-causing events on close X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP When the last subscriber to a "Through" port has been removed, the subscribed destination ports might still be active, so it would be wrong to send "all sounds off" and "reset controller" events to them. The proper place for such a shutdown would be the closing of the actual MIDI port (and close_substream() in rawmidi.c already can do this). This also fixes a deadlock when dummy_unuse() tries to send events to its own port that is already locked because it is being freed. Reported-by: Peter Billam Fixes: 1da177e4c3f4 Cc: Signed-off-by: Clemens Ladisch --- sound/core/seq/seq_dummy.c | 31 ------------------------------- 1 file changed, 31 deletions(-) diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c index ec667f1..5d905d9 100644 --- a/sound/core/seq/seq_dummy.c +++ b/sound/core/seq/seq_dummy.c @@ -82,36 +82,6 @@ struct snd_seq_dummy_port { static int my_client = -1; /* - * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events - * to subscribers. - * Note: this callback is called only after all subscribers are removed. - */ -static int -dummy_unuse(void *private_data, struct snd_seq_port_subscribe *info) -{ - struct snd_seq_dummy_port *p; - int i; - struct snd_seq_event ev; - - p = private_data; - memset(&ev, 0, sizeof(ev)); - if (p->duplex) - ev.source.port = p->connect; - else - ev.source.port = p->port; - ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; - ev.type = SNDRV_SEQ_EVENT_CONTROLLER; - for (i = 0; i < 16; i++) { - ev.data.control.channel = i; - ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF; - snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); - ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS; - snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); - } - return 0; -} - -/* * event input callback - just redirect events to subscribers */ static int @@ -175,7 +145,6 @@ create_port(int idx, int type) | SNDRV_SEQ_PORT_TYPE_PORT; memset(&pcb, 0, sizeof(pcb)); pcb.owner = THIS_MODULE; - pcb.unuse = dummy_unuse; pcb.event_input = dummy_input; pcb.private_free = dummy_free; pcb.private_data = rec;