While most phandle references in common bindings point to the supplier
device node, there are also common bindings where the phandle can
pointing to a child node of the supplier device node.

Therefore, when trying to find the supplier device that corresponds to a
supplier phandle, we need to make sure we are using the supplier's
device node. Otherwise, we'll never find the supplier device.

Signed-off-by: Saravana Kannan <sarava...@google.com>
---
 drivers/of/platform.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 98414ba53b1f..cf8625abe30c 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -529,19 +529,33 @@ static int of_link_binding(struct device *dev,
                           const char *binding, const char *cell)
 {
        struct of_phandle_args sup_args;
+       struct device_node *sup_np;
        struct platform_device *sup_dev;
        unsigned int i = 0, links = 0;
        u32 dl_flags = DL_FLAG_AUTOPROBE_CONSUMER;
 
        while (!of_parse_phandle_with_args(dev->of_node, binding, cell, i,
                                           &sup_args)) {
-               if (!of_link_is_valid(dev->of_node, sup_args.np)) {
-                       of_node_put(sup_args.np);
+               sup_np = sup_args.np;
+               /*
+                * Since we are trying to create device links, we need to find
+                * the actual device node that owns this supplier phandle.
+                * Often times it's the same node, but sometimes it can be one
+                * of the parents. So walk up the parent till you find a
+                * device.
+                */
+               while (sup_np && !of_find_property(sup_np, "compatible", NULL))
+                       sup_np = of_get_next_parent(sup_np);
+               if (!sup_np)
+                       continue;
+
+               if (!of_link_is_valid(dev->of_node, sup_np)) {
+                       of_node_put(sup_np);
                        continue;
                }
                i++;
-               sup_dev = of_find_device_by_node(sup_args.np);
-               of_node_put(sup_args.np);
+               sup_dev = of_find_device_by_node(sup_np);
+               of_node_put(sup_np);
                if (!sup_dev)
                        continue;
                if (device_link_add(dev, &sup_dev->dev, dl_flags))
-- 
2.22.0.510.g264f2c817a-goog

Reply via email to