Re: [PATCH v6 02/10] PCI: imx6: Fix i.MX8MP PCIe EP's occasional failure to trigger MSI

Manivannan Sadhasivam
2024-06-29T13:05:33Z

On Mon, Jun 17, 2024 at 04:16:38PM -0400, Frank Li wrote:
> From: Richard Zhu <hongxing.zhu@nxp.com>
>
> Correct occasional MSI triggering failures in i.MX8MP PCIe EP by apply 64KB
> hardware alignment requirement.
>
> MSI triggering fail if the outbound MSI memory region (ep->msi_mem) is not
> aligned to 64KB.
>
> In dw_pcie_ep_init():
>
> ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
> epc->mem->window.page_size);
>

So this is an alignment restriction w.r.t iATU. In that case, we should be
passing 'pci_epc_features::align' instead?

- Mani

> Set ep->page_size to match drvdata::epc_features::align since different
> SOCs have different alignment requirements.
>
> Fixes: 1bd0d43dcf3b ("PCI: imx6: Clean up addr_space retrieval code")
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Acked-by: Jason Liu <jason.hui.liu@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 9a71b8aa09b3c..ca9a000c9a96d 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1118,6 +1118,8 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
> if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_SUPPORT_64BIT))
> dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
>
> + ep->page_size = imx6_pcie->drvdata->epc_features->align;
> +
> ret = dw_pcie_ep_init(ep);
> if (ret) {
> dev_err(dev, "failed to initialize endpoint\n");
>
> --
> 2.34.1
>

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