The 'cmax' and 'max' are in wrong order and that might cause the used_buses to become negative in certain cases. It should be the same as we do in the block following this one. Fix this. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000 Fixes: 3374c545c27c ("PCI: Account for all bridges on bus when distributing bus numbers") Reported-by: Chris Chiu <chris.chiu@xxxxxxxxxxxxx> Tested-by: Chris Chiu <chris.chiu@xxxxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> --- drivers/pci/probe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c5286b027f00..4f940dcd102c 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2920,8 +2920,8 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, * hotplug bridges too much during the second scan below. */ used_buses++; - if (cmax - max > 1) - used_buses += cmax - max - 1; + if (max - cmax > 1) + used_buses += max - cmax - 1; } /* Scan bridges that need to be reconfigured */ -- 2.35.1