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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4138EF8A15E for ; Thu, 16 Apr 2026 11:13:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:Content-Type: Content-Transfer-Encoding:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jGVHqOPs/4jMGkcftvgjRX5BCFrejfz9iGaZzDJBg8s=; b=KKXQ9kyfUUZDMm3CxXvaCf2+Kk HAmkoOIuWzGxzjAmdH4ozFlJCTIt/JZfxgi2SjIyE4CyOok9VKP9YVKzFS8QjMinGxZPgW/gOQXb4 B2OwfSsgsM77W2UCbAKlCbOMPO5vvOD5r48p682jq8I2IRTwTodfW2YRjSrcVqk7om3yO6LNiqRoj y6bS0GFDaZhmCHVVMi9f5t7IO7qVyDvQNbaMvNgvkBJVTlnVKEvM9wNt64GL88IO/pBoPzwE9/Wqz UaH7b2bbY2rF+me8ugcCbY1NiYzP9vtW6+n8VsFj0MT6PeQYT1G+4JG+U4LJOhqVMg0afACmZbNC2 C3hQUeEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wDKeq-00000002Ls1-1hZR; Thu, 16 Apr 2026 11:13:16 +0000 Received: from mail-northeuropeazon11011029.outbound.protection.outlook.com ([52.101.65.29] helo=DU2PR03CU002.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wDKen-00000002Lpf-3H5N for linux-arm-kernel@lists.infradead.org; Thu, 16 Apr 2026 11:13:14 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=O2DdRnPfjAmOoCR9fPmv3GgwWcCn67ol1rdLgkImDsadPMJrcgQtFNd+rYBmuyTL2PVhB1rb+ysAycBvQXbZNlnhijKeGoCNyIc8Mni52etVOSEQMgIugJrgWXc4sqxPtJg8abW1mX9zQd9fzKdplIPQ7UazK9Ot8LWOlrYzdUTEKjcDY9JkdASYPuOkz/i016qlgrrDQnKW0buXTDwRbGmaebhkUfPmxYaH5GmgPRVqkngKMY1ACsBv8TaNHEbAHS4+aYk+PtMbPN0O9DWiZrIF2DGPPe6t90YIHHZinyx3ZK4F19NQ+gkE5VbHy7r2mPosgUMCc32i6LIghOT0mw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=jGVHqOPs/4jMGkcftvgjRX5BCFrejfz9iGaZzDJBg8s=; b=FMSTzmPdqfz/fy8l9vfrqUbSaIJ2G67odFLr6zVKU5SCmNHGUyiu1qhi9BnGyYx0X6HwGysYp8IBd0M8rl4GtO2uBtqIkrxfQDkiCtDcPBViIXGrbk7+CNfCo0WmRWpkvmsQBdhYaWj9L9Szxmm107eLkaBBUm3jQoEud6VRrDMbz6ABW/iWEixhtvMgtuIq2AUVy4NzeJ11BEeM5m23YmqKuOjZaxCoqLBNOkA+wuL2k+OgE6NEqID7zAVPz7pj95MMwNlol0bIMBYes6nHd2O37aAaSrwmRCxRkAgEnWJXkbsIzwLDma8Q8mfH9qNkeyfxx1ad1/4bobk074/DOA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=jGVHqOPs/4jMGkcftvgjRX5BCFrejfz9iGaZzDJBg8s=; b=nTiCyp4st81yTX7ACgopFjVtUd5tYEVE0oSYuubPscjDF4TwornARmmsGmKjAc68ubGm01o+c1ycXtvTFsLgcOA1znMphBXvRXXDa2SPzeBADwww9L03cKRwcT+EpJfC3MaubBE+jYzevOKVA2c3GwqOW24o5a9kPWbkXnAdCMHDYQFWof2HnEuIl+b96SWMRzVl5r0I6xz7366b/3n5X6/6/1qFnys6f227KeqWX+bxq7PHYnk5KNTa+Ps9R9jSNzkDysXrOKgcDX4Vm2FoJeGU6Nuf83uAKe4tj70c7avIJsgBuMd31DOYDkOoTXTnjD1xL0F/729HefG4FxOARg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from VI0PR04MB12114.eurprd04.prod.outlook.com (2603:10a6:800:315::13) by AS8PR04MB8804.eurprd04.prod.outlook.com (2603:10a6:20b:42f::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9818.25; Thu, 16 Apr 2026 11:13:07 +0000 Received: from VI0PR04MB12114.eurprd04.prod.outlook.com ([fe80::feda:fd0e:147f:f994]) by VI0PR04MB12114.eurprd04.prod.outlook.com ([fe80::feda:fd0e:147f:f994%6]) with mapi id 15.20.9818.023; Thu, 16 Apr 2026 11:13:07 +0000 From: Sherry Sun To: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, Frank.Li@nxp.com, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org, bhelgaas@google.com, hongxing.zhu@nxp.com, l.stach@pengutronix.de Cc: imx@lists.linux.dev, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V13 03/12] PCI: imx6: Assert PERST# before enabling regulators Date: Thu, 16 Apr 2026 19:14:13 +0800 Message-Id: <20260416111422.183860-4-sherry.sun@nxp.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20260416111422.183860-1-sherry.sun@nxp.com> References: <20260416111422.183860-1-sherry.sun@nxp.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: MA0PR01CA0076.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a01:ad::17) To VI0PR04MB12114.eurprd04.prod.outlook.com (2603:10a6:800:315::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: VI0PR04MB12114:EE_|AS8PR04MB8804:EE_ X-MS-Office365-Filtering-Correlation-Id: df8c594e-962a-428c-4506-08de9ba92360 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|52116014|7416014|1800799024|19092799006|18002099003|56012099003|22082099003|38350700014|921020; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI0PR04MB12114.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(366016)(52116014)(7416014)(1800799024)(19092799006)(18002099003)(56012099003)(22082099003)(38350700014)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?/pvjZxRQ4W+wL95iu+5oZnw6hK2m1Ofp0pziWQkxdK1sJgoIDZa+UIOq1O0I?= =?us-ascii?Q?6pkUnuX1gZZtjNvw6tJp7pIdZKpe/zMbKwYvHmCNHpVcrjvOsaD7KNLnVyBz?= =?us-ascii?Q?urRhiOqpirDzUKC16Mv0QSr52Aqn3zazo1+Cd8TxDrjoy8lwqVOGwYYHEOSr?= =?us-ascii?Q?hKTwdD+QaLIAL5UNp6mG12ZJju80GKd5tutCoxcfTUp7/Jml7qHy9645FVTH?= =?us-ascii?Q?fXIEM/nliMGYfvbBdpTX18Kv7J2NZVsTUY2xyo6aguBDacntx+wVX+ikyHoV?= =?us-ascii?Q?sfcE2siNFMiWkeXmpOW7evax/Zs19e/a3TLgX+GwMmDRWRvCVDDZROlSOByN?= =?us-ascii?Q?1x0EgJbbrmPuZHCDRmyC/XwxFV74abaxn69D4F9HjiKr6VlBB7HThmGolAu8?= =?us-ascii?Q?KgOKX6YnMsUdHOCp2JZE7nV18uOPzqi5T4bLMQHiX7jE4kL/LSkN2zsyvmux?= =?us-ascii?Q?/iAlKW73VQc5+zds2TWkt93bCEML5MqxmVIF3I+bggRWoWnVYNlXyU+Cr2/4?= =?us-ascii?Q?voB3FUcZYZRy7+EQeUfP/+TRhrM8rPTwoF2aU/mm35/zSTkOAS0YeAzmiVGV?= =?us-ascii?Q?+XrvmVJUwyMCT88wp6MYU4gXdGMjQ04hJk0m4piFcXfbyBFVJI5V8U9R+JYu?= =?us-ascii?Q?ok5lvqiq3rf0mceMZP06qbY+w7BiTd/c7TF4X4Y3GPxLaCyZoRlg/z1CyDKh?= =?us-ascii?Q?9z0wFrln1qHFLYe7NWuNX2pnRGgBpCTesd3y4L61heRfUt3lDZcIFEmOK+WS?= =?us-ascii?Q?raajIaMb+Yc31nvJ4QANMjWfFgZ0YxK55+cQbO9JVGo1mA+WVPCkK1e1uKJj?= =?us-ascii?Q?zc5xv5tc4lbV/nM+47vvTOo0Yv6dVnIz8hFouippnqzstiJFE2YxdbkldDex?= =?us-ascii?Q?ec+GmN4M2j9zWOy84tyXvNmnPTQsfZ625lFCDWrFAf37Oj3kvZlxQnD6q8iI?= =?us-ascii?Q?txGKkviRuGA+i+LKYE76K4ocVeNiunVqkJJ9YZ0gBTJu6DGVqmgs3j1wqYPY?= =?us-ascii?Q?+fBfVop7jSkmvjkel56AAjFTj977xzcrMen0yIPjYk+MvNTjZc46v7fbdQsz?= =?us-ascii?Q?XzErdSKrD6QuoxPwlaQZLvTf6QyvQb8kH1bqGJzriVmKZMTYbDlVHMsBEwRQ?= =?us-ascii?Q?G+09QARJmYPYhy+wlWYv/Kp5ZzdaxKaD9CJxPKQyMfARlCvMl/kb+U9TxIyR?= =?us-ascii?Q?85NhRRs9adxCv84KFjZeFJGKLIXAhRQf6K8T5/Ny5+yGAs9C6q12W7mpfuZN?= =?us-ascii?Q?veEdfS7rGFZjhZBS/5vgUQhrb16v6BPWNHF/6iMusYP69/3Ud0fThqnxIVHy?= =?us-ascii?Q?V1j5FUVZBPcJfVOpm4ASd5dF9E+F/e9jKguMobQLmFkABGqSTWEExujKB8GB?= =?us-ascii?Q?P73nAg1+eRvD691SfRAw5X9svIV+ApQP399oEVn2Oi3s5tiqwQVinzD8kQyD?= =?us-ascii?Q?rGQ884WEi3bohJK0TaCeMdOXZTjLcbAr4nibIgllJwJ9gL+zWujEca1co1x8?= =?us-ascii?Q?FENfqRLR+hsn+V1PHEo1uveKG/CdnhQq6tLn7P+yo0LRKy6I2omJVes9haYx?= =?us-ascii?Q?l4NG1Dm80raFvIekLAtMslqu9OqIsc7fq34uSQ9jYRQU717JdT4kNBim4qTA?= =?us-ascii?Q?B26/WQeAOgTZpY+TbP1FKqjBkjsmi94CY5erXEJDmfHQ6lYW2zSvcOFapTAD?= =?us-ascii?Q?F8gWNe73hXQPu/0QlIMtwpKtIavkoSWmQYrZCZX3HN7fCIAD0FP4/vATva+s?= =?us-ascii?Q?iXO59HSlEw=3D=3D?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: df8c594e-962a-428c-4506-08de9ba92360 X-MS-Exchange-CrossTenant-AuthSource: VI0PR04MB12114.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Apr 2026 11:13:07.9233 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: r/1N35lPVHHduUoTj5pJi1xDAXgeS5jeSDjk+un6/vayCTJU6stbklaHXq++IjnPa5MgIB6fU88npZ5sdlWKlw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR04MB8804 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260416_041313_822363_09470BAC X-CRM114-Status: GOOD ( 17.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The PCIe endpoint may start responding or driving signals as soon as its supply is enabled, even before the reference clock is stable. Asserting PERST# before enabling the regulator ensures that the endpoint remains in reset throughout the entire power-up sequence, until both power and refclk are known to be stable and link initialization can safely begin. Currently, the driver enables the vpcie3v3aux regulator in imx_pcie_probe() before PERST# is asserted in imx_pcie_host_init(), which may cause PCIe endpoint undefined behavior during early power-up. However, there is no issue so far because PERST# is requested as GPIOD_OUT_HIGH in imx_pcie_probe(), which guarantees that PERST# is asserted before enabling the vpcie3v3aux regulator. This is prepare for the upcoming changes that will parse the reset property using the new Root Port binding, which will use GPIOD_ASIS when requesting the reset GPIO. With GPIOD_ASIS, the GPIO state is not guaranteed, so explicit sequencing is required. Fix the power sequencing by: 1. Moving vpcie3v3aux regulator enable from probe to imx_pcie_host_init(), where it can be properly sequenced with PERST#. 2. Moving imx_pcie_assert_perst() before regulator and clock enable to ensure correct ordering. Signed-off-by: Sherry Sun --- drivers/pci/controller/dwc/pci-imx6.c | 49 +++++++++++++++++++++------ 1 file changed, 39 insertions(+), 10 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index e35044cc5218..735127ed1455 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -168,6 +168,8 @@ struct imx_pcie { u32 tx_swing_full; u32 tx_swing_low; struct regulator *vpcie; + struct regulator *vpcie_aux; + bool vpcie_aux_enabled; struct regulator *vph; void __iomem *phy_base; @@ -1222,6 +1224,13 @@ static void imx_pcie_disable_device(struct pci_host_bridge *bridge, imx_pcie_remove_lut(imx_pcie, pci_dev_id(pdev)); } +static void imx_pcie_vpcie_aux_disable(void *data) +{ + struct regulator *vpcie_aux = data; + + regulator_disable(vpcie_aux); +} + static void imx_pcie_assert_perst(struct imx_pcie *imx_pcie, bool assert) { if (assert) { @@ -1242,6 +1251,24 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp) struct imx_pcie *imx_pcie = to_imx_pcie(pci); int ret; + imx_pcie_assert_perst(imx_pcie, true); + + /* Keep 3.3Vaux supply enabled for the entire PCIe controller lifecycle */ + if (imx_pcie->vpcie_aux && !imx_pcie->vpcie_aux_enabled) { + ret = regulator_enable(imx_pcie->vpcie_aux); + if (ret) { + dev_err(dev, "failed to enable vpcie_aux regulator: %d\n", + ret); + return ret; + } + imx_pcie->vpcie_aux_enabled = true; + + ret = devm_add_action_or_reset(dev, imx_pcie_vpcie_aux_disable, + imx_pcie->vpcie_aux); + if (ret) + return ret; + } + if (imx_pcie->vpcie) { ret = regulator_enable(imx_pcie->vpcie); if (ret) { @@ -1251,25 +1278,24 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp) } } + ret = imx_pcie_clk_enable(imx_pcie); + if (ret) { + dev_err(dev, "unable to enable pcie clocks: %d\n", ret); + goto err_reg_disable; + } + if (pp->bridge && imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT)) { pp->bridge->enable_device = imx_pcie_enable_device; pp->bridge->disable_device = imx_pcie_disable_device; } imx_pcie_assert_core_reset(imx_pcie); - imx_pcie_assert_perst(imx_pcie, true); if (imx_pcie->drvdata->init_phy) imx_pcie->drvdata->init_phy(imx_pcie); imx_pcie_configure_type(imx_pcie); - ret = imx_pcie_clk_enable(imx_pcie); - if (ret) { - dev_err(dev, "unable to enable pcie clocks: %d\n", ret); - goto err_reg_disable; - } - if (imx_pcie->phy) { ret = phy_init(imx_pcie->phy); if (ret) { @@ -1782,9 +1808,12 @@ static int imx_pcie_probe(struct platform_device *pdev) of_property_read_u32(node, "fsl,max-link-speed", &pci->max_link_speed); imx_pcie->supports_clkreq = of_property_read_bool(node, "supports-clkreq"); - ret = devm_regulator_get_enable_optional(&pdev->dev, "vpcie3v3aux"); - if (ret < 0 && ret != -ENODEV) - return dev_err_probe(dev, ret, "failed to enable Vaux supply\n"); + imx_pcie->vpcie_aux = devm_regulator_get_optional(&pdev->dev, "vpcie3v3aux"); + if (IS_ERR(imx_pcie->vpcie_aux)) { + if (PTR_ERR(imx_pcie->vpcie_aux) != -ENODEV) + return PTR_ERR(imx_pcie->vpcie_aux); + imx_pcie->vpcie_aux = NULL; + } imx_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie"); if (IS_ERR(imx_pcie->vpcie)) { -- 2.37.1