Update FORWARD_COLLISION_WARNING_ENABLED documentation in HAL
Temporary errors should be conveyed through ErrorState values in the
STATE property.
Bug: 264946034
Test: presubmit
Change-Id: I720dd691bc859d3113fa48f0f5b9a0b4a909d952
diff --git a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
index 269408e..92dc8a7 100644
--- a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
+++ b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleProperty.aidl
@@ -3499,9 +3499,10 @@
* Set true to enable FCW and false to disable FCW. When FCW is enabled, the ADAS system in the
* vehicle should be turned on and monitoring for potential collisions.
*
- * If FCW is not available, IVehicle#get must not return any NOT_AVAILABLE value in StatusCode.
- * Other StatusCode values like TRY_AGAIN may still be used as needed. For example, if FCW is
- * not available because the vehicle speed is too low, IVehicle#get must return false.
+ * In general, FORWARD_COLLISION_WARNING_ENABLED should always return true or false. If the
+ * feature is not available due to some temporary state, such as the vehicle speed being too
+ * low, that information must be conveyed through the ErrorState values in the
+ * FORWARD_COLLISION_WARNING_STATE property.
*
* This property is defined as read_write, but OEMs have the option to implement it as read
* only.