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 <hongxing.zhu@xxxxxxx> --- 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@xxxxxxx/ --- 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 *imx6_pcie) usleep_range(1000, 10000); } +static void imx6_pcie_msi_save_restore(struct imx6_pcie *imx6_pcie, bool save) +{ + u8 offset; + u16 val; + struct dw_pcie *pci = imx6_pcie->pci; + + if (pci_msi_enabled()) { + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI); + if (save) { + val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS); + imx6_pcie->msi_ctrl = val; + } else { + dw_pcie_dbi_ro_wr_en(pci); + val = 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 = 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; + 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 = imx6_pcie_host_init(pp); if (ret) return ret; + imx6_pcie_msi_save_restore(imx6_pcie, false); dw_pcie_setup_rc(pp); if (imx6_pcie->link_is_up) -- 2.25.1
