Commit 7456427a authored Apr 20, 2020 by Nicolas Saenz Julienne Committed by Rob Herring Apr 28, 2020

of: property: Do not link to disabled devices



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: a3e1d1a7 ("of: property: Add functional dependency link from DT bindings")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Rob Herring <robh@kernel.org>

parent ed365572

drivers/of/property.c

+13 −1

Original line number	Diff line number	Diff line
		@@ -1045,8 +1045,20 @@ 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 to a disabled supplier */
		if (!of_device_is_available(sup_np)) {
		of_node_put(sup_np);
		sup_np = NULL;
		}

		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;

Admin message