From: Nicolas Saenz Julienne Date: Mon, 20 Apr 2020 12:01:02 +0000 (+0200) Subject: of: property: Do not link to disabled devices X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7456427af9def0fec5508dd8b861556038ee96a8;p=linux.git 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: a3e1d1a7f5fc ("of: property: Add functional dependency link from DT bindings") Signed-off-by: Nicolas Saenz Julienne Reviewed-by: Saravana Kannan Signed-off-by: Rob Herring --- diff --git a/drivers/of/property.c b/drivers/of/property.c index 9674b3cf500d4..1f2086f4e7ce8 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;