Messages in this thread Patch in this message | | | From | Nicolas Saenz Julienne <> | Subject | [PATCH v2 2/2] of: property: Do not link to disabled devices | Date | Fri, 17 Apr 2020 18:54:42 +0200 |
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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>
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Changes since v1: - Move availability check into the compatible search routine and bail if device node disabled
drivers/of/property.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/of/property.c b/drivers/of/property.c index dc034eb45defd..14b6266dd054b 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1045,8 +1045,25 @@ 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 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; + } + + 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; -- 2.26.0
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