From patchwork Wed Jan 17 12:50:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Reichl X-Patchwork-Id: 10169245 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 60A79601D3 for ; Wed, 17 Jan 2018 12:51:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F5122859E for ; Wed, 17 Jan 2018 12:51:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CA7E285AF; Wed, 17 Jan 2018 12:51:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EECFB2859E for ; Wed, 17 Jan 2018 12:51:00 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 1FA9D266E73; Wed, 17 Jan 2018 13:50:58 +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 76BBC266E7D; Wed, 17 Jan 2018 13:50:56 +0100 (CET) Received: from mail.horus.com (mail.horus.com [78.46.148.228]) by alsa0.perex.cz (Postfix) with ESMTP id 6BF85266E42 for ; Wed, 17 Jan 2018 13:50:52 +0100 (CET) Received: from [192.168.1.20] (193-83-0-133.adsl.highway.telekom.at [193.83.0.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "E-Mail Matthias Reichl", Issuer "HiassofT CA 2014" (verified OK)) by mail.horus.com (Postfix) with ESMTPS id 68CAD640AD; Wed, 17 Jan 2018 13:50:51 +0100 (CET) Received: by camel2.lan (Postfix, from userid 1000) id C00091C7A44; Wed, 17 Jan 2018 13:50:50 +0100 (CET) From: Matthias Reichl To: Mark Brown , Eric Anholt , Stefan Wahren Date: Wed, 17 Jan 2018 13:50:50 +0100 Message-Id: <20180117125050.2948-1-hias@horus.com> X-Mailer: git-send-email 2.11.0 Cc: alsa-devel@alsa-project.org, Phil Elwell , linux-rpi-kernel@lists.infradead.org Subject: [alsa-devel] [PATCH] ASoC: bcm2835: fix hw_params error when device is in prepared state 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: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP If bcm2835 is configured as bitclock master calling hw_params() after prepare() fails with EBUSY. This also makes it impossible to use bcm2835 in full duplex mode. The error is caused by the split clock setup: clk_set_rate is called in hw_params, clk_prepare_enable in prepare. As hw_params doesn't check if the clock was already enabled clk_set_rate fails with EBUSY. Fix this by moving clock startup from prepare to hw_params and let hw_params properly deal with an already set up or enabled clock. Signed-off-by: Matthias Reichl --- sound/soc/bcm/bcm2835-i2s.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c index 2e449d7173fc..d5f73a8ab893 100644 --- a/sound/soc/bcm/bcm2835-i2s.c +++ b/sound/soc/bcm/bcm2835-i2s.c @@ -130,6 +130,7 @@ struct bcm2835_i2s_dev { struct regmap *i2s_regmap; struct clk *clk; bool clk_prepared; + int clk_rate; }; static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev) @@ -419,10 +420,19 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, } /* Clock should only be set up here if CPU is clock master */ - if (bit_clock_master) { - ret = clk_set_rate(dev->clk, bclk_rate); - if (ret) - return ret; + if (bit_clock_master && + (!dev->clk_prepared || dev->clk_rate != bclk_rate)) { + if (dev->clk_prepared) + bcm2835_i2s_stop_clock(dev); + + if (dev->clk_rate != bclk_rate) { + ret = clk_set_rate(dev->clk, bclk_rate); + if (ret) + return ret; + dev->clk_rate = bclk_rate; + } + + bcm2835_i2s_start_clock(dev); } /* Setup the frame format */ @@ -618,8 +628,6 @@ static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream, struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai); uint32_t cs_reg; - bcm2835_i2s_start_clock(dev); - /* * Clear both FIFOs if the one that should be started * is not empty at the moment. This should only happen