Re: [PATCH] PCI: of: Update parent unit address generation in of_pci_prop_intr_map()

[Lorenzo Pieralisi <lpieralisi@kernel.org>]

On Mon, Aug 18, 2025 at 11:35:04AM +0200, Lorenzo Pieralisi wrote:

[...]

>  drivers/pci/of_property.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/of_property.c b/drivers/pci/of_property.c
> index 506fcd507113..09b7bc335ec5 100644
> --- a/drivers/pci/of_property.c
> +++ b/drivers/pci/of_property.c
> @@ -279,13 +279,20 @@ static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,
>  			mapp++;
>  			*mapp = out_irq[i].np->phandle;
>  			mapp++;
> -			if (addr_sz[i]) {
> -				ret = of_property_read_u32_array(out_irq[i].np,
> -								 "reg", mapp,
> -								 addr_sz[i]);
> -				if (ret)
> -					goto failed;
> -			}
> +
> +			/*
> +			 * A device address does not affect the
> +			 * device<->interrupt-controller HW connection for all
> +			 * modern interrupt controllers; moreover, the kernel
> +			 * (ie of_irq_parse_raw()) ignores the values in the
> +			 * parent unit address cells while parsing the interrupt-map
> +			 * property because they are irrelevant for interrupts mapping
> +			 * in modern system.

Rob,

if you apply directly the line above should be "in modern systems" please.

Thanks,
Lorenzo

> +			 *
> +			 * Leave the parent unit address initialized to 0 - just
> +			 * take into account the #address-cells size to build
> +			 * the property properly.
> +			 */
>  			mapp += addr_sz[i];
>  			memcpy(mapp, out_irq[i].args,
>  			       out_irq[i].args_count * sizeof(u32));
> -- 
> 2.48.0
>