A hotplugged bridge with many hotplug-capable ports may request reserving more IO space than the machine has. This could be overridden with the "hpiosize=" kernel argument though.
But when BARs are movable, there are no need to reserve space anymore: new BARs are allocated not from reserved gaps, but via rearranging the existing BARs. Requesting a precise amount of space for bridge windows increases the chances of adding the new bridge successfully. Signed-off-by: Sergey Miroshnichenko <s.miroshniche...@yadro.com> --- drivers/pci/setup-bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index c7b7e30c6284..7d64ec8e7088 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1287,7 +1287,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) case PCI_HEADER_TYPE_BRIDGE: pci_bridge_check_ranges(bus); - if (bus->self->is_hotplug_bridge) { + if (bus->self->is_hotplug_bridge && !pci_movable_bars_enabled()) { additional_io_size = pci_hotplug_io_size; additional_mem_size = pci_hotplug_mem_size; } -- 2.21.0