For preconfigured PCI bridge, child bus created on the first scan. While for some reasons(e.g register mutation), the secondary, and subordiante register reset to 0 on the second scan, which caused to create PCI bus twice for the same PCI device. Following is the related log: [Wed May 28 20:38:36 CST 2025] pci 0000:0b:01.0: PCI bridge to [bus 0d] [Wed May 28 20:38:36 CST 2025] pci 0000:0b:05.0: bridge configuration invalid ([bus 00-00]), reconfiguring [Wed May 28 20:38:36 CST 2025] pci 0000:0b:01.0: PCI bridge to [bus 0e-10] [Wed May 28 20:38:36 CST 2025] pci 0000:0b:05.0: PCI bridge to [bus 0f-10] Here PCI device 000:0b:01.0 assigend to bus 0d and 0e. This patch checks if child PCI bus has been created on the second scan of bridge. If yes, return directly instead of create a new one. Signed-off-by: Rui He <rui.he@xxxxxxxxxxxxx> --- drivers/pci/probe.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index f41128f91ca76..ec67adbf31738 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1444,6 +1444,9 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, goto out; } + if(pci_has_subordinate(dev)) + goto out; + /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); -- 2.43.0
