From: Nicolas Saenz Julienne nsaenzjulienne@suse.de
[ Upstream commit 7456427af9def0fec5508dd8b861556038ee96a8 ]
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@suse.de Reviewed-by: Saravana Kannan saravanak@google.com Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/of/property.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/of/property.c b/drivers/of/property.c index a8c2b13521b27..6dc542af5a70f 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -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;