pci: Avoid a crash in device_is_on_pci_bus()

This function cannot currently be called on the root node. Add a check
for this as well as a test.

Signed-off-by: Simon Glass <[email protected]>
Reviewed-by: Wolfgang Wallner <[email protected]>
Reviewed-by: Bin Meng <[email protected]>

2 files changed, 15 insertions, 1 deletions

diff --git a/include/dm/device.h b/include/dm/device.h
index f5738a0cee9..953706cf525 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -764,7 +764,7 @@ int dev_enable_by_path(const char *path);
  */
 static inline bool device_is_on_pci_bus(const struct udevice *dev)
 {
-	return device_get_uclass_id(dev->parent) == UCLASS_PCI;
+	return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
 }
 
 /**
diff --git a/test/dm/pci.c b/test/dm/pci.c
index fb93e4c78ae..39e82b3699f 100644
--- a/test/dm/pci.c
+++ b/test/dm/pci.c
@@ -339,3 +339,17 @@ static int dm_test_pci_addr_live(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_pci_addr_live, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT |
 		DM_TESTF_LIVE_TREE);
+
+/* Test device_is_on_pci_bus() */
+static int dm_test_pci_on_bus(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(dm_pci_bus_find_bdf(PCI_BDF(0, 0x1f, 0), &dev));
+	ut_asserteq(true, device_is_on_pci_bus(dev));
+	ut_asserteq(false, device_is_on_pci_bus(dev_get_parent(dev)));
+	ut_asserteq(true, device_is_on_pci_bus(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_pci_on_bus, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);