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=-13.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED,USER_AGENT_GIT 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 954E7C4320A for ; Tue, 17 Aug 2021 16:41:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77DB06044F for ; Tue, 17 Aug 2021 16:41:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231239AbhHQQlw (ORCPT ); Tue, 17 Aug 2021 12:41:52 -0400 Received: from mga06.intel.com ([134.134.136.31]:38258 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229991AbhHQQlu (ORCPT ); Tue, 17 Aug 2021 12:41:50 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10079"; a="277170639" X-IronPort-AV: E=Sophos;i="5.84,329,1620716400"; d="scan'208";a="277170639" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2021 09:41:16 -0700 X-IronPort-AV: E=Sophos;i="5.84,329,1620716400"; d="scan'208";a="449342732" Received: from aaadelek-mobl3.amr.corp.intel.com (HELO pbossart-mobl3.intel.com) ([10.212.12.89]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2021 09:41:15 -0700 From: Pierre-Louis Bossart To: alsa-devel@alsa-project.org Cc: tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, liam.r.girdwood@linux.intel.com, Kuninori Morimoto , Pierre-Louis Bossart , Liam Girdwood , Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org (open list) Subject: [RFC PATCH 2/2] ASoC: soc-pcm: test refcount before triggering Date: Tue, 17 Aug 2021 11:40:54 -0500 Message-Id: <20210817164054.250028-3-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210817164054.250028-1-pierre-louis.bossart@linux.intel.com> References: <20210817164054.250028-1-pierre-louis.bossart@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On start/pause_release/resume, when more than one FE is connected to the same BE, it's possible that the trigger is sent more than once. This is not desirable, we only want to trigger a BE once, which is straightforward to implement with a refcount. For stop/pause/suspend, the problem is more complicated: the check implemented in snd_soc_dpcm_can_be_free_stop() may fail due to a conceptual deadlock when we trigger the BE before the FE. In this case, the FE states have not yet changed, so there are corner cases where the TRIGGER_STOP is never sent - the dual case of start where multiple triggers might be sent. This patch suggests an unconditional trigger in all cases, without checking the FE states, using a refcount protected by a spinlock. Signed-off-by: Pierre-Louis Bossart --- include/sound/soc-dpcm.h | 2 ++ sound/soc/soc-pcm.c | 46 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 44 insertions(+), 4 deletions(-) diff --git a/include/sound/soc-dpcm.h b/include/sound/soc-dpcm.h index e296a3949b18..6cc751002da7 100644 --- a/include/sound/soc-dpcm.h +++ b/include/sound/soc-dpcm.h @@ -101,6 +101,8 @@ struct snd_soc_dpcm_runtime { enum snd_soc_dpcm_state state; int trigger_pending; /* trigger cmd + 1 if pending, 0 if not */ + + int be_start; /* refcount protected by dpcm_lock */ }; #define for_each_dpcm_fe(be, stream, _dpcm) \ diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 0717f39d2eec..b2440f2f9bf5 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1534,7 +1534,7 @@ int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream) be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE; goto unwind; } - + be->dpcm[stream].be_start = 0; be->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN; count++; } @@ -2001,6 +2001,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, int ret = 0; unsigned long flags; enum snd_soc_dpcm_state state; + bool do_trigger; for_each_dpcm_be(fe, stream, dpcm) { struct snd_pcm_substream *be_substream; @@ -2015,6 +2016,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, dev_dbg(be->dev, "ASoC: trigger BE %s cmd %d\n", be->dai_link->name, cmd); + do_trigger = false; switch (cmd) { case SNDRV_PCM_TRIGGER_START: spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2025,13 +2027,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, continue; } state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2045,13 +2054,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, } state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2065,13 +2081,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, } state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); + if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2084,9 +2107,15 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if ((be->dpcm[stream].state == SND_SOC_DPCM_STATE_START && + be->dpcm[stream].be_start == 1) || + (be->dpcm[stream].state == SND_SOC_DPCM_STATE_PAUSED && + be->dpcm[stream].be_start == 0)) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); - if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue; spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2098,6 +2127,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2109,9 +2139,12 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if (be->dpcm[stream].be_start == 1) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); - if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue; spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2123,6 +2156,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2134,9 +2168,12 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if (be->dpcm[stream].be_start == 1) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); - if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue; spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2148,6 +2185,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } -- 2.25.1