1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index e282886616a..750c346ef50 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -606,6 +606,16 @@ static void __init __pci_mmcfg_init(int early)
         if (list_empty(&pci_mmcfg_list))
                 return;
 
+        if (pcibios_last_bus < 0) {
+                const struct pci_mmcfg_region *cfg;
+
+                list_for_each_entry(cfg, &pci_mmcfg_list, list) {
+                        if (cfg->segment)
+                                break;
+                        pcibios_last_bus = cfg->end_bus;
+                }
+        }
+
         if (pci_mmcfg_arch_init())
                 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
         else {