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@xxxxxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Signed-off-by: Rob Herring <robh@xxxxxxxxxx> --- 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) -- 2.30.2
