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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: a3e1d1a7f5 ("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>
This commit is contained in:
Nicolas Saenz Julienne 2020-04-20 14:01:02 +02:00 committed by Rob Herring
parent ed36557291
commit 7456427af9
1 changed files with 13 additions and 1 deletions
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14
drivers/of/property.c
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@ -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;