ACPI: device property: Fix node lookup in acpi_graph_get_child_prop_value()

acpi_graph_get_child_prop_value() is intended to find a child node with a
certain property value pair. The check

	if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
		continue;

is faulty: fwnode_property_read_u32() returns zero on success, not on
failure, leading to comparing values only if the searched property was not
found.

Moreover, the check is made against the parent device node instead of
the child one as it should be.

Fixes: 79389a83bc38 (ACPI / property: Add support for remote endpoints)
Reported-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: 4.12+ <stable@vger.kernel.org> # 4.12+
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 917c789f953dfb280f6f00895ce1fcf7ae2484ec..476a52c60cf3de98b18abe2c35a681c2be3ae058 100644 (file)
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1047,7 +1047,7 @@ static struct fwnode_handle *acpi_graph_get_child_prop_value(
        fwnode_for_each_child_node(fwnode, child) {
                u32 nr;
 
        fwnode_for_each_child_node(fwnode, child) {
                u32 nr;
 

-               if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
+               if (fwnode_property_read_u32(child, prop_name, &nr))

                        continue;
 
                if (val == nr)
                        continue;
 
                if (val == nr)