ACPI: property: Ignore already existing data node tags

ACPI node pointers are attached to data node handles, in order to resolve
string references to them. _DSD guide allows the same node to be reached
from multiple parent nodes, leading the node enumeration algorithm to each
such nodes more than once. As attached data already already exists,
attaching data with the same tag will fail. Address this problem by
ignoring nodes that have been already tagged.

Fixes: 1d52f10917a7 ("ACPI: property: Tie data nodes to acpi handles")
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index b1d4a8db89df509f07c0655c9c7cb86e28c4e26f..91d0e75859d375d5bee4d89b3849246a288292b9 100644 (file)
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -370,7 +370,7 @@ static bool acpi_tie_nondev_subnodes(struct acpi_device_data *data)
                bool ret;
 
                status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn);
-               if (ACPI_FAILURE(status)) {
+               if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
                        acpi_handle_err(dn->handle, "Can't tag data node\n");
                        return false;
                }