Re: Aw: Re: [PATCH] pci: mediatek: fix warning in msi.h

From: Thomas Gleixner
Date: Mon Nov 02 2020 - 11:17:04 EST


On Mon, Nov 02 2020 at 11:30, Marc Zyngier wrote:
> On 2020-11-01 22:27, Thomas Gleixner wrote:
> The following patch makes it work for me (GICv3 guest without an ITS)by
> checking for the presence of an MSI domain at the point where we
> actually
> perform this association, and before starting to scan for endpoints.
>
> I *think* this should work for the MTK thingy, but someone needs to
> go and check.
>
> Thanks,
>
> M.
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 4289030b0fff..bb363eb103a2 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -871,6 +871,8 @@ static void pci_set_bus_msi_domain(struct pci_bus
> *bus)
> d = pci_host_bridge_msi_domain(b);
>
> dev_set_msi_domain(&bus->dev, d);
> + if (!d)
> + bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;

Hrm, that might break legacy setups (no irqdomain support). I'd rather
prefer to explicitly tell the pci core at host registration time.

Bjorn?

Thanks,

tglx