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

[Frank Li <Frank.li@nxp.com>]

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:
> > 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
> 
> > 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
> > 
> 
> -- 
> மணிவண்ணன் சதாசிவம்