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

On Sat, Jun 29, 2024 at 06:35:25PM +0530, Manivannan Sadhasivam wrote:

On Mon, Jun 17, 2024 at 04:16:38PM -0400, Frank Li wrote:

quoted

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?

pci_epc_features::align already set.

pci_epc_mem_alloc_addr(
	...
	align_size = ALIGN(size, mem->window.page_size);
	order = pci_epc_mem_get_order(mem, align_size);
	...
}

but pci_epc_mem_alloc_addr() align to page_size, instead of
pci_epc_features::align.

Frank

- Mani

quoted

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 <redacted>
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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