If dependencies inferred by of_fwnode_add_links() result in a cycle, it can prevent the probing of all the devices in the cycle. The depends-on property has been added to explicitly override inferred dependencies when they create a cycle.
Add depends-on parsing support to of_fwnode_add_links() so that platforms with cyclic dependencies can use "depends-on" to break the cycle and continue successfully probing devices. Signed-off-by: Saravana Kannan <[email protected]> --- drivers/of/property.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/of/property.c b/drivers/of/property.c index 420c2d428184..78a262e24686 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1106,6 +1106,12 @@ static struct device_node *parse_interconnects(struct device_node *np, "#interconnect-cells"); } +static struct device_node *parse_depends_on(struct device_node *np, + const char *prop_name, int index) +{ + return parse_prop_cells(np, prop_name, index, "depends-on", NULL); +} + static int strcmp_suffix(const char *str, const char *suffix) { unsigned int len, suffix_len; @@ -1151,6 +1157,7 @@ static const struct supplier_bindings bindings[] = { { .parse_prop = parse_clocks, }, { .parse_prop = parse_interconnects, }, { .parse_prop = parse_regulators, }, + { .parse_prop = parse_depends_on, }, {}, }; @@ -1203,6 +1210,12 @@ static int __of_link_to_suppliers(struct device *dev, struct property *p; int ret = 0; + if (of_find_property(con_np, "depends-on", NULL)) { + if (of_link_property(dev, con_np, "depends-on")) + ret = -EAGAIN; + return ret; + } + for_each_property_of_node(con_np, p) if (of_link_property(dev, con_np, p->name)) ret = -EAGAIN; -- 2.23.0.187.g17f5b7556c-goog
