When creating a consumer/supplier relationship between two devices, make
sure the supplier node is actually active. Otherwise this will create a
device link 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>
---
drivers/of/property.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index a8c2b13521b27..487685ff8bb19 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1052,6 +1052,13 @@ static int of_link_to_phandle(struct device *dev, struct device_node *sup_np,
return -ENODEV;
}
+ /* 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;
+ }
+
/*
* Don't allow linking a device node as a consumer of one of its
* descendant nodes. By definition, a child node can't be a functional
--
2.26.0
