diff --git a/Android.bp b/Android.bp
index 223a1a9..baf3291 100644
--- a/Android.bp
+++ b/Android.bp
@@ -51,7 +51,6 @@
     // Lists all dependencies that can *not* be expected on the device.
     static_libs: [
         "VtsHalHidlTestUtils",
-        "libhidlbase",
         "libhidl-gen-utils",
     ],
 
@@ -64,6 +63,7 @@
         "libbase",
         // All the following are dependencies of any HAL definition library.
         "libcutils",
+        "libhidlbase",
         "liblog",
         "libutils",
     ],
@@ -72,14 +72,6 @@
         "-g",
     ],
 
-    target: {
-        android: {
-            shared_libs: [
-                "libvndksupport",
-            ],
-        },
-    },
-
     require_root: true,
 }
 
diff --git a/audio/aidl/android/hardware/audio/core/StreamDescriptor.aidl b/audio/aidl/android/hardware/audio/core/StreamDescriptor.aidl
index 65ea9ef..cfe001e 100644
--- a/audio/aidl/android/hardware/audio/core/StreamDescriptor.aidl
+++ b/audio/aidl/android/hardware/audio/core/StreamDescriptor.aidl
@@ -386,14 +386,23 @@
          * For input streams: the moment when data at the specified stream position
          *   was acquired (i.e. capture position).
          *
-         * The observable position must never be reset by the HAL module.
-         * The data type of the frame counter is large enough to support
-         * continuous counting for years of operation.
+         * The observable position must never be reset by the HAL module,
+         * providing an abstraction of continuous audio data flow. The data
+         * type of the frame counter is large enough to support continuous
+         * counting for years of operation.
          */
         Position observable;
         /**
          * Used only for MMap streams to provide the hardware read / write
          * position for audio data in the shared memory buffer 'audio.mmap'.
+         * Similar to the observable position, the 'Position::UNKNOWN' value
+         * can be returned when the HAL module is unable to retrieve the current
+         * position.
+         *
+         * The hardware position must never be reset by the HAL module,
+         * providing an abstraction of continuous audio data flow. The data
+         * type of the frame counter is large enough to support continuous
+         * counting for years of operation.
          */
         Position hardware;
         /**