Commit 6a381ea6 authored Jun 22, 2019 by Nicholas Johnson Committed by Bjorn Helgaas Jul 02, 2019

PCI: Skip resource distribution when no hotplug bridges

If "hotplug_bridges == 0", "!dev->is_hotplug_bridge" is always true, so the
loop that divides the remaining resources among hotplug-capable bridges
does nothing.

Check for "hotplug_bridges == 0" earlier, so we don't even have to compute
the amount of remaining resources. No functional change intended.

Link: https://lore.kernel.org/r/PS2P216MB0642C7A485649D2D787A1C6F80000@PS2P216MB0642.KORP216.PROD.OUTLOOK.COM
Link: https://lore.kernel.org/r/20190622210310.180905-3-helgaas@kernel.org

Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

parent 5c6bcc34

drivers/pci/setup-bus.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1892,6 +1892,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
		return;
		}

		if (hotplug_bridges == 0)
		return;

		/*
		* Calculate the total amount of extra resource space we can
		* pass to bridges below this one. This is basically the
		@@ -1941,8 +1944,6 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
		* Distribute available extra resources equally between
		* hotplug-capable downstream ports taking alignment into
		* account.
		*
		* Here hotplug_bridges is always != 0.
		*/
		align = pci_resource_alignment(bridge, io_res);
		io = div64_ul(available_io, hotplug_bridges);