From 49ad31e9d78527045614c534df057cadee487773 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 5 Sep 2022 11:02:28 +0300 Subject: [PATCH] PCI: Pass available buses even if the bridge is already configured If some part of the PCI topology is already configured (by the boot firmware) but not all, and it includes hotplug bridges, we may need to extend the bus resources of those bridges to accommodate any future hotplugs, in the same way we already do with the normal hotplug case. Pass the available buses to pci_scan_child_bus_extend() even when the bridge in question is already configured so the bus allocation code can use these available buses to extend the possible hotplug bridges below. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000 Link: https://lore.kernel.org/r/20220905080232.36087-3-mika.westerberg@linux.intel.com Reported-by: Chris Chiu Tested-by: Chris Chiu Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko --- drivers/pci/probe.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 4f940dcd102c..86130926a74f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1297,7 +1297,7 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, if ((secondary || subordinate) && !pcibios_assign_all_busses() && !is_cardbus && !broken) { - unsigned int cmax; + unsigned int cmax, buses; /* * Bus already configured by firmware, process it in the @@ -1322,7 +1322,8 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, child->bridge_ctl = bctl; } - cmax = pci_scan_child_bus(child); + buses = subordinate - secondary; + cmax = pci_scan_child_bus_extend(child, buses); if (cmax > subordinate) pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n", subordinate, cmax);