When creating a consumer/supplier relationship between two devices,
make sure the supplier node is actually active. Otherwise this will
create a link relationship that will never be fulfilled. This, in the
worst case scenario, will hang the system during boot.
Note that, in practice, the fact that a device-tree represented
consumer/supplier relationship isn't fulfilled will not prevent devices
from successfully probing.
Fixes: a3e1d1a7f5fc ("of: property: Add functional dependency link from DT bindings")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
---
Changes since v1:
- Move availability check into the compatible search routine and bail
if device node disabled
drivers/of/property.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index dc034eb45defd..14b6266dd054b 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1045,8 +1045,25 @@ static int of_link_to_phandle(struct device *dev, struct device_node *sup_np,
* Find the device node that contains the supplier phandle. It may be
* @sup_np or it may be an ancestor of @sup_np.
*/
- while (sup_np && !of_find_property(sup_np, "compatible", NULL))
+ while (sup_np) {
+
+ /*
+ * Don't allow linking a device node as consumer of a disabled
+ * node.
+ */
+ if (!of_device_is_available(sup_np)) {
+ dev_dbg(dev, "Not linking to %pOFP - Not available\n",
+ sup_np);
+ of_node_put(sup_np);
+ return -ENODEV;
+ }
+
+ if (of_find_property(sup_np, "compatible", NULL))
+ break;
+
sup_np = of_get_next_parent(sup_np);
+ }
+
if (!sup_np) {
dev_dbg(dev, "Not linking to %pOFP - No device\n", tmp_np);
return -ENODEV;
--
2.26.0
