Re: [PATCH] PCI: of: Fix MSI domain lookup with child bus nodes

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Fri, 13 Aug 2021 11:02:57 -0500
Rob Herring <robh@kernel.org> escreveu:

> When a DT contains PCI child bus nodes, lookup of the MSI domain on PCI
> buses fails resulting in the following warnings:
> 
> WARNING: CPU: 4 PID: 7 at include/linux/msi.h:256 __pci_enable_msi_range+0x398/0x59c
> 
> The issue is that pci_host_bridge_of_msi_domain() will check the DT node of
> the passed in bus even if it's not the host bridge's bus. Based on the
> name of the function, that's clearly not what we want. Fix this by
> walking the bus parents to the root bus.
> 
> Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> Compile tested only. Mauro, Can you see if this fixes your issue.
> 
>  drivers/pci/of.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index a143b02b2dcd..ea70aede054c 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -84,6 +84,10 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
>  	if (!bus->dev.of_node)
>  		return NULL;
>  
> +	/* Find the host bridge bus */
> +	while (!pci_is_root_bus(bus))
> +		bus = bus->parent;
> +
>  	/* Start looking for a phandle to an MSI controller. */
>  	d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
>  	if (d)

Nope, it didn't solve the issue.


Thanks,
Mauro