MIPS: PCI: Fix pcibios_scan_bus() NULL check code path

Lorenzo Pieralisi · bjorn-helgaas · commit 902d886d4474 · 2017-07-31T14:37:53.000-05:00
If pci_scan_root_bus() fails (ie returns NULL) pcibios_scan_bus() must return immediately since the struct pci_bus pointer it returns is not valid and cannot be used. Move code checking the pci_scan_root_bus() return value to reinstate proper pcibios_scanbus() error path behaviour. Fixes: 88555b4 ("MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC") Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com>
diff --git a/arch/mips/pci/pci-legacy.c b/arch/mips/pci/pci-legacy.c
@@ -89,16 +89,16 @@ static void pcibios_scanbus(struct pci_controller *hose)
 	pci_add_resource(&resources, hose->busn_resource);
 	bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose,
 				&resources);
-	hose->bus = bus;
-
-	need_domain_info = need_domain_info || pci_domain_nr(bus);
-	set_pci_need_domain_info(hose, need_domain_info);
-
 	if (!bus) {
 		pci_free_resource_list(&resources);
 		return;
 	}
 
+	hose->bus = bus;
+
+	need_domain_info = need_domain_info || pci_domain_nr(bus);
+	set_pci_need_domain_info(hose, need_domain_info);
+
 	next_busno = bus->busn_res.end + 1;
 	/* Don't allow 8-bit bus number overflow inside the hose -
 	   reserve some space for bridges. */
