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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 11250C433DB for ; Fri, 19 Mar 2021 01:38:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDA2A64E77 for ; Fri, 19 Mar 2021 01:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230018AbhCSBiP (ORCPT ); Thu, 18 Mar 2021 21:38:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229884AbhCSBh5 (ORCPT ); Thu, 18 Mar 2021 21:37:57 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C95EC06174A for ; Thu, 18 Mar 2021 18:37:57 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 546AA4FD; Fri, 19 Mar 2021 02:37:55 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1616117875; bh=Thu4D/gcRRsbB+L0SIeYzvGUWd62xfEsqC7314uIkow=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hQUqiLdN1WXbE1yq6Vp1mvoIrlhXYKoCIGLGbT7XObzRG5LsNq304MvDnPVD3Xn6I AAMRoAFJzGMdnI8fvUhvNTsmOg/yjCccqQ+Gb656QQjGJr2KbOa6Jvx1pTUNQZAAUz xjG5Z3JfybboQiyx+coFV99MOU/ZFE+rdGu+XsV4= Date: Fri, 19 Mar 2021 03:37:17 +0200 From: Laurent Pinchart To: Manish Narani Cc: kishon@ti.com, vkoul@kernel.org, michal.simek@xilinx.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, git@xilinx.com Subject: Re: [PATCH v2] phy: zynqmp: Handle the clock enable/disable properly Message-ID: References: <1615288664-45034-1-git-send-email-manish.narani@xilinx.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1615288664-45034-1-git-send-email-manish.narani@xilinx.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Manish, Thank you for the patch. On Tue, Mar 09, 2021 at 04:47:44PM +0530, Manish Narani wrote: > The current driver is not handling the clock enable/disable operations > properly. The clocks need to be handled correctly by enabling or > disabling at appropriate places. This patch adds code to handle the > same. > > Signed-off-by: Manish Narani > --- > drivers/phy/xilinx/phy-zynqmp.c | 57 ++++++++++++++++++++++++++++++++++++----- > 1 file changed, 50 insertions(+), 7 deletions(-) > > diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c > index 2b65f84..37fcecf 100644 > --- a/drivers/phy/xilinx/phy-zynqmp.c > +++ b/drivers/phy/xilinx/phy-zynqmp.c > @@ -219,6 +219,7 @@ struct xpsgtr_dev { > struct mutex gtr_mutex; /* mutex for locking */ > struct xpsgtr_phy phys[NUM_LANES]; > const struct xpsgtr_ssc *refclk_sscs[NUM_LANES]; > + struct clk *clk[NUM_LANES]; > bool tx_term_fix; > unsigned int saved_icm_cfg0; > unsigned int saved_icm_cfg1; > @@ -818,11 +819,15 @@ static struct phy *xpsgtr_xlate(struct device *dev, > static int __maybe_unused xpsgtr_suspend(struct device *dev) > { > struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev); > + unsigned int i; > > /* Save the snapshot ICM_CFG registers. */ > gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0); > gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1); > > + for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) > + clk_disable_unprepare(gtr_dev->clk[i]); > + > return 0; > } > > @@ -832,6 +837,13 @@ static int __maybe_unused xpsgtr_resume(struct device *dev) > unsigned int icm_cfg0, icm_cfg1; > unsigned int i; > bool skip_phy_init; > + int err; > + > + for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) { > + err = clk_prepare_enable(gtr_dev->clk[i]); > + if (err) > + goto err_clk_put; > + } > > icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0); > icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1); > @@ -852,6 +864,12 @@ static int __maybe_unused xpsgtr_resume(struct device *dev) > gtr_dev->phys[i].skip_phy_init = skip_phy_init; > > return 0; > + > +err_clk_put: > + for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) > + clk_disable_unprepare(gtr_dev->clk[i]); You should only disable the clocks that have been successfully enabled. Something like this should do: while (i-- > 0) clk_disable_unprepare(gtr_dev->clk[i]); > + > + return err; > } > > static const struct dev_pm_ops xpsgtr_pm_ops = { > @@ -865,6 +883,7 @@ static const struct dev_pm_ops xpsgtr_pm_ops = { > static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev) > { > unsigned int refclk; > + int ret; > > for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->refclk_sscs); ++refclk) { > unsigned long rate; > @@ -874,14 +893,22 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev) > > snprintf(name, sizeof(name), "ref%u", refclk); > clk = devm_clk_get_optional(gtr_dev->dev, name); > - if (IS_ERR(clk)) > - return dev_err_probe(gtr_dev->dev, PTR_ERR(clk), > - "Failed to get reference clock %u\n", > - refclk); > + if (IS_ERR(clk)) { > + ret = dev_err_probe(gtr_dev->dev, PTR_ERR(clk), > + "Failed to get reference clock %u\n", > + refclk); > + goto err_clk_put; > + } > > if (!clk) > continue; > > + gtr_dev->clk[refclk] = clk; > + > + ret = clk_prepare_enable(gtr_dev->clk[refclk]); > + if (ret) > + goto err_clk_put; > + > /* > * Get the spread spectrum (SSC) settings for the reference > * clock rate. > @@ -899,11 +926,18 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev) > dev_err(gtr_dev->dev, > "Invalid rate %lu for reference clock %u\n", > rate, refclk); > - return -EINVAL; > + ret = -EINVAL; > + goto err_clk_put; > } > } > > return 0; > + > +err_clk_put: > + for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->clk); refclk++) > + clk_disable_unprepare(gtr_dev->clk[refclk]); Here too you will disable a clock that hasn't been enabled if clk_prepare_enable() failed. Clocks that haven't been retrieved at all are fine, as clk_disable_unprepare() can be safely called with a NULL pointer. This could be fixed by replacing the code above with ret = clk_prepare_enable(clk); if (ret) goto err_clk_put; gtr_dev->clk[refclk] = clk; > + > + return ret; > } > > static int xpsgtr_probe(struct platform_device *pdev) > @@ -912,6 +946,7 @@ static int xpsgtr_probe(struct platform_device *pdev) > struct xpsgtr_dev *gtr_dev; > struct phy_provider *provider; > unsigned int port; > + unsigned int i; > int ret; > > gtr_dev = devm_kzalloc(&pdev->dev, sizeof(*gtr_dev), GFP_KERNEL); > @@ -951,7 +986,8 @@ static int xpsgtr_probe(struct platform_device *pdev) > phy = devm_phy_create(&pdev->dev, np, &xpsgtr_phyops); > if (IS_ERR(phy)) { > dev_err(&pdev->dev, "failed to create PHY\n"); > - return PTR_ERR(phy); > + ret = PTR_ERR(phy); > + goto err_clk_put; > } > > gtr_phy->phy = phy; > @@ -962,9 +998,16 @@ static int xpsgtr_probe(struct platform_device *pdev) > provider = devm_of_phy_provider_register(&pdev->dev, xpsgtr_xlate); > if (IS_ERR(provider)) { > dev_err(&pdev->dev, "registering provider failed\n"); > - return PTR_ERR(provider); > + ret = PTR_ERR(provider); > + goto err_clk_put; > } > return 0; > + > +err_clk_put: > + for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) > + clk_disable_unprepare(gtr_dev->clk[i]); > + > + return ret; > } > > static const struct of_device_id xpsgtr_of_match[] = { -- Regards, Laurent Pinchart