Re: [PATCH] PCI: dwc: Fix inner MSI IRQ domain registration

[Lorenzo Pieralisi]

On Fri, May 01, 2020 at 12:39:21PM +0100, Marc Zyngier wrote:
> On a system that uses the internal DWC MSI widget, I get this
> warning from debugfs when CONFIG_GENERIC_IRQ_DEBUGFS is selected:
> 
>   debugfs: File ':soc:pcie@fc000000' in directory 'domains' already present!
> 
> This is due to the fact that the DWC MSI code tries to register two
> IRQ domains for the same firmware node, without telling the low
> level code how to distinguish them (by setting a bus token). This
> further confuses debugfs which tries to create corresponding
> files for each domain.
> 
> Fix it by tagging the inner domain as DOMAIN_BUS_NEXUS, which is
> the closest thing we have as to "generic MSI".
> 
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 2 ++
>  1 file changed, 2 insertions(+)

Applied to pci/dwc, thanks !

Lorenzo

> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 395feb8ca051..3c43311bb95c 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -264,6 +264,8 @@ int dw_pcie_allocate_domains(struct pcie_port *pp)
>  		return -ENOMEM;
>  	}
>  
> +	irq_domain_update_bus_token(pp->irq_domain, DOMAIN_BUS_NEXUS);
> +
>  	pp->msi_domain = pci_msi_create_irq_domain(fwnode,
>  						   &dw_pcie_msi_domain_info,
>  						   pp->irq_domain);
> -- 
> 2.26.2
>