diff --git a/core/java/android/hardware/camera2/CaptureRequest.java b/core/java/android/hardware/camera2/CaptureRequest.java
index 6d0d505..93eb3de 100644
--- a/core/java/android/hardware/camera2/CaptureRequest.java
+++ b/core/java/android/hardware/camera2/CaptureRequest.java
@@ -731,6 +731,8 @@
     /**
      * <p>List of areas to use for
      * metering.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AE android.control.maxRegionsAe} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -746,7 +748,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AE
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
@@ -820,6 +824,8 @@
     /**
      * <p>List of areas to use for focus
      * estimation.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AF android.control.maxRegionsAf} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -835,7 +841,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AF
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
@@ -921,6 +929,8 @@
     /**
      * <p>List of areas to use for illuminant
      * estimation.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AWB android.control.maxRegionsAwb} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -936,7 +946,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AWB
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
diff --git a/core/java/android/hardware/camera2/CaptureResult.java b/core/java/android/hardware/camera2/CaptureResult.java
index 754d83e..01276a2 100644
--- a/core/java/android/hardware/camera2/CaptureResult.java
+++ b/core/java/android/hardware/camera2/CaptureResult.java
@@ -582,6 +582,8 @@
     /**
      * <p>List of areas to use for
      * metering.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AE android.control.maxRegionsAe} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -597,7 +599,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AE
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
@@ -870,6 +874,8 @@
     /**
      * <p>List of areas to use for focus
      * estimation.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AF android.control.maxRegionsAf} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -885,7 +891,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AF
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
@@ -1369,6 +1377,8 @@
     /**
      * <p>List of areas to use for illuminant
      * estimation.</p>
+     * <p>Optional. Not available if {@link CameraCharacteristics#CONTROL_MAX_REGIONS_AWB android.control.maxRegionsAwb} is 0.
+     * Otherwise will always be present.</p>
      * <p>The coordinate system is based on the active pixel array,
      * with (0,0) being the top-left pixel in the active pixel array, and
      * ({@link CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE android.sensor.info.activeArraySize}.width - 1,
@@ -1384,7 +1394,9 @@
      * outside the used {@link CaptureRequest#SCALER_CROP_REGION android.scaler.cropRegion} returned in capture result metadata,
      * the camera device will ignore the sections outside the region and output the
      * used sections in the result metadata.</p>
+     * <p><b>Optional</b> - This value may be {@code null} on some devices.</p>
      *
+     * @see CameraCharacteristics#CONTROL_MAX_REGIONS_AWB
      * @see CaptureRequest#SCALER_CROP_REGION
      * @see CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE
      */
diff --git a/core/java/android/hardware/camera2/legacy/LegacyMetadataMapper.java b/core/java/android/hardware/camera2/legacy/LegacyMetadataMapper.java
index a8d1018..3c0e0e4 100644
--- a/core/java/android/hardware/camera2/legacy/LegacyMetadataMapper.java
+++ b/core/java/android/hardware/camera2/legacy/LegacyMetadataMapper.java
@@ -675,15 +675,13 @@
          * request.availableRequestKeys
          */
         {
-            CaptureRequest.Key<?> availableKeys[] = new CaptureRequest.Key<?>[] {
+            CaptureRequest.Key<?> defaultAvailableKeys[] = new CaptureRequest.Key<?>[] {
                     CaptureRequest.CONTROL_AE_ANTIBANDING_MODE,
                     CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION,
                     CaptureRequest.CONTROL_AE_LOCK,
                     CaptureRequest.CONTROL_AE_MODE,
-                    CaptureRequest.CONTROL_AE_REGIONS,
                     CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE,
                     CaptureRequest.CONTROL_AF_MODE,
-                    CaptureRequest.CONTROL_AF_REGIONS,
                     CaptureRequest.CONTROL_AF_TRIGGER,
                     CaptureRequest.CONTROL_AWB_LOCK,
                     CaptureRequest.CONTROL_AWB_MODE,
@@ -704,21 +702,32 @@
                     CaptureRequest.SCALER_CROP_REGION,
                     CaptureRequest.STATISTICS_FACE_DETECT_MODE,
             };
-            m.set(REQUEST_AVAILABLE_REQUEST_KEYS, getTagsForKeys(availableKeys));
+            ArrayList<CaptureRequest.Key<?>> availableKeys =
+                    new ArrayList<CaptureRequest.Key<?>>(Arrays.asList(defaultAvailableKeys));
+
+            if (p.getMaxNumMeteringAreas() > 0) {
+                availableKeys.add(CaptureRequest.CONTROL_AE_REGIONS);
+            }
+            if (p.getMaxNumFocusAreas() > 0) {
+                availableKeys.add(CaptureRequest.CONTROL_AF_REGIONS);
+            }
+
+            CaptureRequest.Key<?> availableRequestKeys[] =
+                    new CaptureRequest.Key<?>[availableKeys.size()];
+            availableKeys.toArray(availableRequestKeys);
+            m.set(REQUEST_AVAILABLE_REQUEST_KEYS, getTagsForKeys(availableRequestKeys));
         }
 
         /*
          * request.availableResultKeys
          */
         {
-            CaptureResult.Key<?> availableKeys[] = new CaptureResult.Key<?>[] {
+            CaptureResult.Key<?> defaultAvailableKeys[] = new CaptureResult.Key<?>[] {
                     CaptureResult.CONTROL_AE_ANTIBANDING_MODE                      ,
                     CaptureResult.CONTROL_AE_EXPOSURE_COMPENSATION                 ,
                     CaptureResult.CONTROL_AE_LOCK                                  ,
                     CaptureResult.CONTROL_AE_MODE                                  ,
-                    CaptureResult.CONTROL_AE_REGIONS                               ,
                     CaptureResult.CONTROL_AF_MODE                                  ,
-                    CaptureResult.CONTROL_AF_REGIONS                               ,
                     CaptureResult.CONTROL_AF_STATE                                 ,
                     CaptureResult.CONTROL_AWB_MODE                                 ,
                     CaptureResult.CONTROL_AWB_LOCK                                 ,
@@ -737,7 +746,20 @@
                     CaptureResult.STATISTICS_FACE_DETECT_MODE                      ,
 //                    CaptureResult.STATISTICS_FACES                                 ,
             };
-            m.set(REQUEST_AVAILABLE_RESULT_KEYS, getTagsForKeys(availableKeys));
+            List<CaptureResult.Key<?>> availableKeys =
+                    new ArrayList<CaptureResult.Key<?>>(Arrays.asList(defaultAvailableKeys));
+
+            if (p.getMaxNumMeteringAreas() > 0) {
+                availableKeys.add(CaptureResult.CONTROL_AE_REGIONS);
+            }
+            if (p.getMaxNumFocusAreas() > 0) {
+                availableKeys.add(CaptureResult.CONTROL_AF_REGIONS);
+            }
+
+            CaptureResult.Key<?> availableResultKeys[] =
+                    new CaptureResult.Key<?>[availableKeys.size()];
+            availableKeys.toArray(availableResultKeys);
+            m.set(REQUEST_AVAILABLE_RESULT_KEYS, getTagsForKeys(availableResultKeys));
         }
 
         /*
diff --git a/core/java/android/hardware/camera2/legacy/LegacyResultMapper.java b/core/java/android/hardware/camera2/legacy/LegacyResultMapper.java
index 090a822..ddaa6ee 100644
--- a/core/java/android/hardware/camera2/legacy/LegacyResultMapper.java
+++ b/core/java/android/hardware/camera2/legacy/LegacyResultMapper.java
@@ -322,7 +322,7 @@
         }
 
         // control.aeRegions
-        {
+        if (p.getMaxNumMeteringAreas() > 0) {
             if (VERBOSE) {
                 String meteringAreas = p.get("metering-areas");
                 Log.v(TAG, "mapAe - parameter dump; metering-areas: " + meteringAreas);
@@ -342,7 +342,7 @@
         m.set(CaptureResult.CONTROL_AF_MODE, convertLegacyAfMode(p.getFocusMode()));
 
         // control.afRegions
-        {
+        if (p.getMaxNumFocusAreas() > 0) {
             if (VERBOSE) {
                 String focusAreas = p.get("focus-areas");
                 Log.v(TAG, "mapAe - parameter dump; focus-areas: " + focusAreas);