Re: [PATCH v5 06/19] PCI/MSI: of: Allow msi_domain lookup using the host bridge node

Bjorn Helgaas
2015-07-23T13:13:53Z

On Thu, Jul 23, 2015 at 10:26:25AM +0100, Marc Zyngier wrote:
> A number of platforms do not need to use the msi-parent property,
> as the host bridge itself provides the MSI controller.
>
> Allow this configuration by performing an irq domain lookup based
> on the host bridge node if it doesn't have a valid msi-parent property.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
> drivers/pci/of.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index e2ebb7d..fcfdadf 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -69,12 +69,21 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
>
> if (!bus->dev.of_node)
> return NULL;
> +
> + /* Start looking for a phandle to an MSI controller. */
> np = of_parse_phandle(bus->dev.of_node, "msi-parent", 0);
> +
> + /*
> + * If we don't have an msi-parent property, look for a domain
> + * directly attached to the host bridge.
> + */
> if (!np)
> - return NULL;
> + np = bus->dev.of_node;
> +
> d = irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
> if (!d)
> d = irq_find_host(np);
> +
> return d;
> #else
> return NULL;
> --
> 2.1.4
>