From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
[ Upstream commit 23583f7795025e3c783b680d906509366b0906ad ]
When the DSDT tables expose devices with subdevices and a set of hierarchical _DSD properties, the data returned by acpi_get_next_subnode() is incorrect, with the results suggesting a bad pointer assignment. The parser works fine with device_nodes or data_nodes, but not with a combination of the two.
The problem is traced to an invalid pointer used when jumping from handling device_nodes to data nodes. The existing code looks for data nodes below the last subdevice found instead of the common root. Fix by forcing the acpi_device pointer to be derived from the same fwnode for the two types of subnodes.
This same problem of handling device and data nodes was already fixed in a similar way by 'commit bf4703fdd166 ("ACPI / property: fix data node parsing in acpi_get_next_subnode()")' but broken later by 'commit 34055190b19 ("ACPI / property: Add fwnode_get_next_child_node()")', so this should probably go to linux-stable all the way to 4.12
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/property.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 693cf05b0cc44..288673cff85ea 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -975,6 +975,14 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode, const struct acpi_data_node *data = to_acpi_data_node(fwnode); struct acpi_data_node *dn;
+ /* + * We can have a combination of device and data nodes, e.g. with + * hierarchical _DSD properties. Make sure the adev pointer is + * restored before going through data nodes, otherwise we will + * be looking for data_nodes below the last device found instead + * of the common fwnode shared by device_nodes and data_nodes. + */ + adev = to_acpi_device_node(fwnode); if (adev) head = &adev->data.subnodes; else if (data)