From nobody Thu Sep 18 07:20:34 2025 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 36B06C3A5A7 for ; Thu, 8 Dec 2022 06:28:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229777AbiLHG2Q (ORCPT ); Thu, 8 Dec 2022 01:28:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229731AbiLHG2O (ORCPT ); Thu, 8 Dec 2022 01:28:14 -0500 Received: from inva021.nxp.com (inva021.nxp.com [92.121.34.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DBBF47300; Wed, 7 Dec 2022 22:28:13 -0800 (PST) Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id E5F332004CB; Thu, 8 Dec 2022 07:28:11 +0100 (CET) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id B0A5A2005B7; Thu, 8 Dec 2022 07:28:11 +0100 (CET) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 6380D180031D; Thu, 8 Dec 2022 14:28:10 +0800 (+08) From: Richard Zhu To: l.stach@pengutronix.de, bhelgaas@google.com, lorenzo.pieralisi@arm.com Cc: hongxing.zhu@nxp.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, linux-imx@nxp.com Subject: [PATCH v2] PCI: imx6: Save and restore MSI control of RC in suspend and resume Date: Thu, 8 Dec 2022 14:05:34 +0800 Message-Id: <1670479534-22154-1-git-send-email-hongxing.zhu@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The MSI Enable bit controls delivery of MSI interrupts from components below the Root Port. This bit might lost during the suspend, should be re-stored during resume. Save the MSI control during suspend, and restore it in resume. Signed-off-by: Richard Zhu --- Changes v1-->v2: New create one save/restore function, used save the setting in suspend and restore the configuration in resume. v1 https://patchwork.kernel.org/project/linux-pci/patch/1667289595-12440-1-= git-send-email-hongxing.zhu@nxp.com/ --- drivers/pci/controller/dwc/pci-imx6.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller= /dwc/pci-imx6.c index 1dde5c579edc..aa3096890c3b 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -76,6 +76,7 @@ struct imx6_pcie { struct clk *pcie; struct clk *pcie_aux; struct regmap *iomuxc_gpr; + u16 msi_ctrl; u32 controller_id; struct reset_control *pciephy_reset; struct reset_control *apps_reset; @@ -1042,6 +1043,26 @@ static void imx6_pcie_pm_turnoff(struct imx6_pcie *i= mx6_pcie) usleep_range(1000, 10000); } =20 +static void imx6_pcie_msi_save_restore(struct imx6_pcie *imx6_pcie, bool s= ave) +{ + u8 offset; + u16 val; + struct dw_pcie *pci =3D imx6_pcie->pci; + + if (pci_msi_enabled()) { + offset =3D dw_pcie_find_capability(pci, PCI_CAP_ID_MSI); + if (save) { + val =3D dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS); + imx6_pcie->msi_ctrl =3D val; + } else { + dw_pcie_dbi_ro_wr_en(pci); + val =3D imx6_pcie->msi_ctrl; + dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val); + dw_pcie_dbi_ro_wr_dis(pci); + } + } +} + static int imx6_pcie_suspend_noirq(struct device *dev) { struct imx6_pcie *imx6_pcie =3D dev_get_drvdata(dev); @@ -1050,6 +1071,7 @@ static int imx6_pcie_suspend_noirq(struct device *dev) if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_SUPPORTS_SUSPEND)) return 0; =20 + imx6_pcie_msi_save_restore(imx6_pcie, true); imx6_pcie_pm_turnoff(imx6_pcie); imx6_pcie_stop_link(imx6_pcie->pci); imx6_pcie_host_exit(pp); @@ -1069,6 +1091,7 @@ static int imx6_pcie_resume_noirq(struct device *dev) ret =3D imx6_pcie_host_init(pp); if (ret) return ret; + imx6_pcie_msi_save_restore(imx6_pcie, false); dw_pcie_setup_rc(pp); =20 if (imx6_pcie->link_is_up) --=20 2.25.1