Re: [PATCH v2 1/4] PCI: rcar-gen4: Configure AXIINTC if iMSI-RX not used

[Marek Vasut]

On 6/30/26 8:04 PM, Geert Uytterhoeven wrote:

Hello Geert,

> > +static int rcar_gen4_pcie_host_msi_addr(struct dw_pcie_rp *pp, u32 *msi_addr)
> > +{
> > +       struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
> > +       struct device_node *msi_node = NULL;
> > +       struct device *dev = dw->dev;
> > +       struct resource res;
> > +       u64 addr;
> > +       int ret;
> > +
> > +       /*
> > +        * Either the "msi-parent" or the "msi-map" phandle needs to exist
> > +        * to obtain the MSI node.
> > +        */
> > +       of_msi_xlate(dev, &msi_node, 0);
> > +       if (!msi_node)
> > +               return -ENODEV;
>
> This is not backwards-compatible with existing DTBs.
> I noticed because PCIe is broken on Gray Hawk Single with R-Car V4M
> after this series.  Indeed, "[PATCH v2 4/4] arm64: dts: renesas:
> r8a779g0: Add GICv3 ITS and update PCIe nodes" only covers R-Car V4H,
> but not R-Car S4-8 and R-Car V4M.
Thank you for spotting this, and, this code is not supposed to be 
reached. It turns out, pp->use_imsi_rx is not assigned yet in the .init 
callback. I hope this is addressed in V3 with a new patch:

[PATCH v3 1/5] PCI: dwc: Determine whether iMSI is used before calling .init