From: Thomas Gleixner <t...@linutronix.de>

Some PCI host bridges cannot deal with MSIs at all. This has
the unfortunate effect of triggering ugly warnings when an end-point
driver requests MSIs.

Instead, let the bridge advertise such lack of MSIs, so that it
can be flagged correctly by the core code.

Acked-by: Bjorn Helgaas <bhelg...@google.com>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
[maz: commit message]
Signed-off-by: Marc Zyngier <m...@kernel.org>
---
 drivers/pci/probe.c | 2 ++
 include/linux/pci.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index fb04fc81a8bd..146bd85c037e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -925,6 +925,8 @@ static int pci_register_host_bridge(struct pci_host_bridge 
*bridge)
        device_enable_async_suspend(bus->bridge);
        pci_set_bus_of_node(bus);
        pci_set_bus_msi_domain(bus);
+       if (bridge->no_msi)
+               bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
 
        if (!parent)
                set_dev_node(bus->bridge, pcibus_to_node(bus));
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ebf557e59d87..48605cca82ae 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -550,6 +550,7 @@ struct pci_host_bridge {
        unsigned int    native_dpc:1;           /* OS may use PCIe DPC */
        unsigned int    preserve_config:1;      /* Preserve FW resource setup */
        unsigned int    size_windows:1;         /* Enable root bus sizing */
+       unsigned int    no_msi:1;               /* Bridge has no MSI support */
 
        /* Resource alignment requirements */
        resource_size_t (*align_resource)(struct pci_dev *dev,
-- 
2.29.2

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