ACPI: property: graph: Improve graph documentation for port/ep numbering
Document that if a port has a single endpoint only, its value shall be
zero. Similarly, if a device object only has a single port, its value
shlla be zero.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt
index 0b007fc..3131f45 100644
--- a/Documentation/acpi/dsd/graph.txt
+++ b/Documentation/acpi/dsd/graph.txt
@@ -55,7 +55,10 @@
Each port node contains a property extension key "port", the value of
which is the number of the port. Each endpoint is similarly numbered
with a property extension key "endpoint". Port numbers must be unique within a
-device and endpoint numbers must be unique within a port.
+device and endpoint numbers must be unique within a port. If a device object
+may only has a single port, then the number of that port shall be zero.
+Similarly, if a port may only have a single endpoint, the number of that
+endpoint shall be zero.
The endpoint reference uses property extension with "remote-endpoint" property
name followed by a reference in the same package. Such references consist of the
