From patchwork Thu Sep 1 11:46:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 9308939 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 F0448607D6 for ; Thu, 1 Sep 2016 11:47:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E46B529310 for ; Thu, 1 Sep 2016 11:47:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D956629313; Thu, 1 Sep 2016 11:47:09 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7D6A729310 for ; Thu, 1 Sep 2016 11:47:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bfQRH-0005LL-6m; Thu, 01 Sep 2016 11:45:47 +0000 Received: from conuserg-08.nifty.com ([210.131.2.75]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bfQQw-0003ta-4D for linux-arm-kernel@lists.infradead.org; Thu, 01 Sep 2016 11:45:28 +0000 Received: from beagle.diag.org (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-08.nifty.com with ESMTP id u81BiPw1020288; Thu, 1 Sep 2016 20:44:26 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-08.nifty.com u81BiPw1020288 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1472730266; bh=bix3bPcT7Bj3haTX8JKzqB4b8c6kgjTrgf3l/mdpd6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=voh18gyoLj41zaAwZRAeCSzuY8bslUR4A9Ic/2aHyEfw1qaieAq3c4cHKKZRL0hLP 18mqSIcc/nT07zQko0JBmTXgMgjocfcWrAUdboGwLXrK9k3hZPGnFEs8n/IPQ6nxnq TQiSPLtvCOTZHUPFX2d9Hte0YOcJDk8MpzLQFs6sP7wD4MVB3rw2Y6atgS5J/x4LSJ MAx/5UHKWkLbsAn9IpB4WQsb2nk+E/a+HjkwAAiC4zko6t7una71h87iVj8v6sVLkB d4SYtL76RTrffh9FZbxGAEiczED8pQDtldZzrr6LeF2lbeiH6noYzTmRVjYlDWzL8V GBg8VEbgjsHJg== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-i2c@vger.kernel.org Subject: [PATCH 1/3] i2c: uniphier: avoid WARN_ON() of clk_disable() in failure path Date: Thu, 1 Sep 2016 20:46:28 +0900 Message-Id: <1472730390-8907-2-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1472730390-8907-1-git-send-email-yamada.masahiro@socionext.com> References: <1472730390-8907-1-git-send-email-yamada.masahiro@socionext.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160901_044526_645868_3B0005B4 X-CRM114-Status: GOOD ( 13.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Masahiro Yamada , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Wolfram Sang MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP If clk_prepare_enable() fails, clk_disable_unprepare() is called in the failure path, where the enable_count is still zero, so it hits WARN_ON(core->enable_count == 0) in the clk_core_disable(). To fix this, make the clock setting more linear in the probe function so that it can exploit "goto err" in case of error. Signed-off-by: Masahiro Yamada --- drivers/i2c/busses/i2c-uniphier.c | 73 +++++++++++++++++---------------------- 1 file changed, 31 insertions(+), 42 deletions(-) diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c index d6e612a..56e92af 100644 --- a/drivers/i2c/busses/i2c-uniphier.c +++ b/drivers/i2c/busses/i2c-uniphier.c @@ -316,50 +316,15 @@ static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = { .unprepare_recovery = uniphier_i2c_unprepare_recovery, }; -static int uniphier_i2c_clk_init(struct device *dev, - struct uniphier_i2c_priv *priv) +static void uniphier_i2c_hw_init(struct uniphier_i2c_priv *priv, + u32 bus_speed, unsigned long clk_rate) { - struct device_node *np = dev->of_node; - unsigned long clk_rate; - u32 bus_speed; - int ret; - - if (of_property_read_u32(np, "clock-frequency", &bus_speed)) - bus_speed = UNIPHIER_I2C_DEFAULT_SPEED; - - if (!bus_speed) { - dev_err(dev, "clock-frequency should not be zero\n"); - return -EINVAL; - } - - if (bus_speed > UNIPHIER_I2C_MAX_SPEED) - bus_speed = UNIPHIER_I2C_MAX_SPEED; - - /* Get input clk rate through clk driver */ - priv->clk = devm_clk_get(dev, NULL); - if (IS_ERR(priv->clk)) { - dev_err(dev, "failed to get clock\n"); - return PTR_ERR(priv->clk); - } - - ret = clk_prepare_enable(priv->clk); - if (ret) - return ret; - - clk_rate = clk_get_rate(priv->clk); - if (!clk_rate) { - dev_err(dev, "input clock rate should not be zero\n"); - return -EINVAL; - } - uniphier_i2c_reset(priv, true); writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed), priv->membase + UNIPHIER_I2C_CLK); uniphier_i2c_reset(priv, false); - - return 0; } static int uniphier_i2c_probe(struct platform_device *pdev) @@ -367,8 +332,9 @@ static int uniphier_i2c_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct uniphier_i2c_priv *priv; struct resource *regs; - int irq; - int ret; + u32 bus_speed; + unsigned long clk_rate; + int irq, ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -385,6 +351,31 @@ static int uniphier_i2c_probe(struct platform_device *pdev) return irq; } + if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed)) + bus_speed = UNIPHIER_I2C_DEFAULT_SPEED; + + if (!bus_speed || bus_speed > UNIPHIER_I2C_MAX_SPEED) { + dev_err(dev, "invalid clock-frequency %d\n", bus_speed); + return -EINVAL; + } + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "failed to get clock\n"); + return PTR_ERR(priv->clk); + } + + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(priv->clk); + if (!clk_rate) { + dev_err(dev, "input clock rate should not be zero\n"); + ret = -EINVAL; + goto err; + } + init_completion(&priv->comp); priv->adap.owner = THIS_MODULE; priv->adap.algo = &uniphier_i2c_algo; @@ -395,9 +386,7 @@ static int uniphier_i2c_probe(struct platform_device *pdev) i2c_set_adapdata(&priv->adap, priv); platform_set_drvdata(pdev, priv); - ret = uniphier_i2c_clk_init(dev, priv); - if (ret) - goto err; + uniphier_i2c_hw_init(priv, bus_speed, clk_rate); ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name, priv);