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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 836FAC00140 for ; Wed, 24 Aug 2022 16:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239027AbiHXQHd (ORCPT ); Wed, 24 Aug 2022 12:07:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239194AbiHXQHZ (ORCPT ); Wed, 24 Aug 2022 12:07:25 -0400 Received: from hutie.ust.cz (unknown [IPv6:2a03:3b40:fe:f0::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54DFA80E82; Wed, 24 Aug 2022 09:07:22 -0700 (PDT) From: =?UTF-8?q?Martin=20Povi=C5=A1er?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cutebit.org; s=mail; t=1661357240; bh=aO38GJDIP/5aJG6S0vIu2Re6vO0yDujEU8aBKTpUOoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Bxm61ZEynvpzn8cGD8yFgOWSblB7WYZYp8swzU6lksYgeFKL2Psl7tZMrQrQOgrEo o3qi86pna0Z+tnErdiyTmXsRMS6yaSjPN4brbS0SN8OLPzluwbGpU2uGRLSkfoeim0 6HGwKNyD5af9aDowtXFhKbnpOaCQnNKr6itIwkgM= To: =?UTF-8?q?Martin=20Povi=C5=A1er?= , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Hector Martin , Sven Peter , Philipp Zabel Cc: Alyssa Rosenzweig , asahi@lists.linux.dev, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 4/4] ASoC: apple: mca: Add locking Date: Wed, 24 Aug 2022 18:07:15 +0200 Message-Id: <20220824160715.95779-5-povik+lin@cutebit.org> In-Reply-To: <20220824160715.95779-1-povik+lin@cutebit.org> References: <20220824160715.95779-1-povik+lin@cutebit.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In DAI ops, accesses to the native cluster (of the DAI), and to data of clusters related to it by a DPCM frontend-backend link, should have been synchronized by the 'pcm_mutex' lock at ASoC level. What is not covered are the 'port_driver' accesses on foreign clusters to which the current cluster has no a priori relation, so fill in locking for that. (This should only matter in bizarre configurations of sharing one MCA peripheral between ASoC cards.) Signed-off-by: Martin PoviĊĦer --- sound/soc/apple/mca.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c index 807b85469408..aa67d57c9a9b 100644 --- a/sound/soc/apple/mca.c +++ b/sound/soc/apple/mca.c @@ -158,6 +158,9 @@ struct mca_data { struct reset_control *rstc; struct device_link *pd_link; + /* Mutex for accessing port_driver of foreign clusters */ + struct mutex port_mutex; + int nclusters; struct mca_cluster clusters[]; }; @@ -296,16 +299,21 @@ static bool mca_fe_clocks_in_use(struct mca_cluster *cl) struct mca_cluster *be_cl; int stream, i; + mutex_lock(&mca->port_mutex); for (i = 0; i < mca->nclusters; i++) { be_cl = &mca->clusters[i]; if (be_cl->port_driver != cl->no) continue; - for_each_pcm_streams(stream) - if (be_cl->clocks_in_use[stream]) + for_each_pcm_streams(stream) { + if (be_cl->clocks_in_use[stream]) { + mutex_unlock(&mca->port_mutex); return true; + } + } } + mutex_unlock(&mca->port_mutex); return false; } @@ -349,6 +357,11 @@ static int mca_be_hw_free(struct snd_pcm_substream *substream, if (cl->port_driver < 0) return -EINVAL; + /* + * We are operating on a foreign cluster here, but since we + * belong to the same PCM, accesses should have been + * synchronized at ASoC level. + */ fe_cl = &mca->clusters[cl->port_driver]; if (!mca_fe_clocks_in_use(fe_cl)) return 0; /* Nothing to do */ @@ -721,7 +734,9 @@ static int mca_be_startup(struct snd_pcm_substream *substream, cl->base + REG_PORT_CLOCK_SEL); writel_relaxed(PORT_DATA_SEL_TXA(fe_cl->no), cl->base + REG_PORT_DATA_SEL); + mutex_lock(&mca->port_mutex); cl->port_driver = fe_cl->no; + mutex_unlock(&mca->port_mutex); cl->port_started[substream->stream] = true; return 0; @@ -731,6 +746,7 @@ static void mca_be_shutdown(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct mca_cluster *cl = mca_dai_to_cluster(dai); + struct mca_data *mca = cl->host; cl->port_started[substream->stream] = false; @@ -741,7 +757,9 @@ static void mca_be_shutdown(struct snd_pcm_substream *substream, */ writel_relaxed(0, cl->base + REG_PORT_ENABLES); writel_relaxed(0, cl->base + REG_PORT_DATA_SEL); + mutex_lock(&mca->port_mutex); cl->port_driver = -1; + mutex_unlock(&mca->port_mutex); } } @@ -962,6 +980,7 @@ static int apple_mca_probe(struct platform_device *pdev) return -ENOMEM; mca->dev = &pdev->dev; mca->nclusters = nclusters; + mutex_init(&mca->port_mutex); platform_set_drvdata(pdev, mca); clusters = mca->clusters; -- 2.33.0