[PATCH v4 33/35] pci: Avoid a crash in device_is_on_pci_bus()

[Simon Glass]

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 <sjg at chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---

(no changes since v1)

 include/dm/device.h |  2 +-
 test/dm/pci.c       | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/dm/device.h b/include/dm/device.h
index f5738a0cee..953706cf52 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 fb93e4c78a..39e82b3699 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);
-- 
2.27.0.383.g050319c2ae-goog