On Tue, Nov 01, 2022 at 03:59:55PM +0800, Richard Zhu wrote:
> 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-configured during resume.
Just out of curiosity, why would this bit "get lost" during suspend?
Don't the normal save and restore in the suspend/resume paths take
care of this? Are there other bits that might get lost?
> Encapsulate the MSI enable set into a standalone function, and invoke it
> in both probe and resume.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 24 +++++++++++++++++-------
> 1 file changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 2616585ca5f8..dba15546075f 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1041,6 +1041,21 @@ static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
> usleep_range(1000, 10000);
> }
>
> +static void pci_imx_set_msi_en(struct dw_pcie *pci)
> +{
> + u8 offset;
> + u16 val;
> +
> + if (pci_msi_enabled()) {
> + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
> + dw_pcie_dbi_ro_wr_en(pci);
> + val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
> + val |= PCI_MSI_FLAGS_ENABLE;
> + 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);
> @@ -1073,6 +1088,7 @@ static int imx6_pcie_resume_noirq(struct device *dev)
> if (imx6_pcie->link_is_up)
> imx6_pcie_start_link(imx6_pcie->pci);
>
> + pci_imx_set_msi_en(imx6_pcie->pci);
> return 0;
> }
>
> @@ -1090,7 +1106,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> struct resource *dbi_base;
> struct device_node *node = dev->of_node;
> int ret;
> - u16 val;
>
> imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
> if (!imx6_pcie)
> @@ -1282,12 +1297,7 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> if (ret < 0)
> return ret;
>
> - if (pci_msi_enabled()) {
> - u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
> - val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
> - val |= PCI_MSI_FLAGS_ENABLE;
> - dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val);
> - }
> + pci_imx_set_msi_en(pci);
>
> return 0;
> }
> --
> 2.25.1
>
>
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