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 64405C77B73 for ; Mon, 8 May 2023 07:00:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232545AbjEHG7t (ORCPT ); Mon, 8 May 2023 02:59:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233255AbjEHG7g (ORCPT ); Mon, 8 May 2023 02:59:36 -0400 Received: from smtp.smtpout.orange.fr (smtp-13.smtpout.orange.fr [80.12.242.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ACF319D71 for ; Sun, 7 May 2023 23:59:24 -0700 (PDT) Received: from [192.168.1.18] ([86.243.2.178]) by smtp.orange.fr with ESMTPA id vuq3pLWu0unMHvuq3pBwg2; Mon, 08 May 2023 08:59:21 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wanadoo.fr; s=t20230301; t=1683529161; bh=Ryhq4eaEWmWDYOdIXBNmYtLvCNROHD7rXvSdIVxOm0c=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=h86uiNgobj8OHnUlZm8V2grAj3q3ci8iC0qVk46uo5eN377DtEykldpJIuRyDuokr yhrzdNzi2PUnQNxexCNSZFyWLPjMBmZ4Cgn7f48hkrWcnm0CslcYwBOubM2H/jwmMo b8Qait6jaUPATs5S5DicF28oXnVoT3O4mQb1o5YB78gBogK34hzFgYUY5SWXZHEOeq TfkcLwDzYEugRZokteWYZGVkdkv3hNroXMqdwBnAQR/Txg/TgU+cVsKmAKeUoMv+lx BYvGWsp7GzM3KBwCsKdHXpwwyk9AfYsMDZLV3r/e/CqFsjL4cCyGZiO+U75EMCr/OS nIHyjGooJiyTA== X-ME-Helo: [192.168.1.18] X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Mon, 08 May 2023 08:59:21 +0200 X-ME-IP: 86.243.2.178 Message-ID: <430d0357-d10e-db3d-bc82-722b022b519b@wanadoo.fr> Date: Mon, 8 May 2023 08:59:15 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v3] pci: controller: pci-ftpci100: Release the clock resources Content-Language: fr, en-US To: Junyan Ye , Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?= , Rob Herring , Bjorn Helgaas , Wei Yongjun , Linus Walleij , Andrew Murray Cc: hust-os-kernel-patches@googlegroups.com, Dongliang Mu , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230508043641.23807-1-yejunyan@hust.edu.cn> From: Christophe JAILLET In-Reply-To: <20230508043641.23807-1-yejunyan@hust.edu.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 08/05/2023 à 06:36, Junyan Ye a écrit : > Smatch reported: > 1. drivers/pci/controller/pci-ftpci100.c:526 faraday_pci_probe() warn: > 'clk' from clk_prepare_enable() not released on lines: 442,451,462,478,512,517. > 2. drivers/pci/controller/pci-ftpci100.c:526 faraday_pci_probe() warn: > 'p->bus_clk' from clk_prepare_enable() not released on lines: 451,462,478,512,517. > > The clock resource is obtained by devm_clk_get(), and then > clk_prepare_enable() makes the clock resource ready for use. After that, > clk_disable_unprepare() should be called to release the clock resource > when it is no longer needed. However, while doing some error handling > in faraday_pci_probe(), clk_disable_unprepare() is not called to release > clk and p->bus_clk before returning. These return lines are exactly 442, > 451, 462, 478, 512, 517. > > Fix this warning by replacing devm_clk_get() with devm_clk_get_enabled(), > which is equivalent to devm_clk_get() + clk_prepare_enable(). And with > devm_clk_get_enabled(), the clock will automatically be disabled, > unprepared and freed when the device is unbound from the bus. > > Fixes: b3c433efb8a3 ("PCI: faraday: Fix wrong pointer passed to PTR_ERR()") > Fixes: 2eeb02b28579 ("PCI: faraday: Add clock handling") > Fixes: 783a862563f7 ("PCI: faraday: Use pci_parse_request_of_pci_ranges()") > Fixes: d3c68e0a7e34 ("PCI: faraday: Add Faraday Technology FTPCI100 PCI Host Bridge driver") > Fixes: f1e8bd21e39e ("PCI: faraday: Convert IRQ masking to raw PCI config accessors") > Reviewed-by: Dongliang Mu > Signed-off-by: Junyan Ye > --- > v2 -> v3: Rebase to v6.4-rc1 and modify commit message. > v1 -> v2: Switch from clk_disable_unprepare() to devm_clk_get_enabled() to release the clock. > This issue is found by static analyzer. > > drivers/pci/controller/pci-ftpci100.c | 14 ++------------ > 1 file changed, 2 insertions(+), 12 deletions(-) > > diff --git a/drivers/pci/controller/pci-ftpci100.c b/drivers/pci/controller/pci-ftpci100.c > index ecd3009df586..6e7981d2ed5e 100644 > --- a/drivers/pci/controller/pci-ftpci100.c > +++ b/drivers/pci/controller/pci-ftpci100.c > @@ -429,22 +429,12 @@ static int faraday_pci_probe(struct platform_device *pdev) > p->dev = dev; > > /* Retrieve and enable optional clocks */ Hi, completely unrelated to your patch, but this comments state "optional". The code below seems to make both clocks mandatory. Moreover, a few lines later, we have: if (!IS_ERR(p->bus_clk)) { which seems to say that bus_clk is optional. This was introduced by 2eeb02b28579. Just a guess, but either the comment should be updated, or the code modified. Just my 2c, CJ > - clk = devm_clk_get(dev, "PCLK"); > + clk = devm_clk_get_enabled(dev, "PCLK"); > if (IS_ERR(clk)) > return PTR_ERR(clk); > - ret = clk_prepare_enable(clk); > - if (ret) { > - dev_err(dev, "could not prepare PCLK\n"); > - return ret; > - } > - p->bus_clk = devm_clk_get(dev, "PCICLK"); > + p->bus_clk = devm_clk_get_enabled(dev, "PCICLK"); > if (IS_ERR(p->bus_clk)) > return PTR_ERR(p->bus_clk); > - ret = clk_prepare_enable(p->bus_clk); > - if (ret) { > - dev_err(dev, "could not prepare PCICLK\n"); > - return ret; > - } > > p->base = devm_platform_ioremap_resource(pdev, 0); > if (IS_ERR(p->base))