diff --git a/core/java/android/hardware/display/BrightnessInfo.java b/core/java/android/hardware/display/BrightnessInfo.java
index c5d37c2..0dc8f92 100644
--- a/core/java/android/hardware/display/BrightnessInfo.java
+++ b/core/java/android/hardware/display/BrightnessInfo.java
@@ -60,12 +60,18 @@
     /** Brightness */
     public final float brightness;
 
+    /** Brightness after {@link DisplayPowerController} adjustments */
+    public final float adjustedBrightness;
+
     /** Current minimum supported brightness. */
     public final float brightnessMinimum;
 
     /** Current maximum supported brightness. */
     public final float brightnessMaximum;
 
+    /** Brightness values greater than this point are only used in High Brightness Mode. */
+    public final float highBrightnessTransitionPoint;
+
     /**
      * Current state of high brightness mode.
      * Can be any of HIGH_BRIGHTNESS_MODE_* values.
@@ -73,11 +79,20 @@
     public final int highBrightnessMode;
 
     public BrightnessInfo(float brightness, float brightnessMinimum, float brightnessMaximum,
-            @HighBrightnessMode int highBrightnessMode) {
+            @HighBrightnessMode int highBrightnessMode, float highBrightnessTransitionPoint) {
+        this(brightness, brightness, brightnessMinimum, brightnessMaximum, highBrightnessMode,
+                highBrightnessTransitionPoint);
+    }
+
+    public BrightnessInfo(float brightness, float adjustedBrightness, float brightnessMinimum,
+            float brightnessMaximum, @HighBrightnessMode int highBrightnessMode,
+            float highBrightnessTransitionPoint) {
         this.brightness = brightness;
+        this.adjustedBrightness = adjustedBrightness;
         this.brightnessMinimum = brightnessMinimum;
         this.brightnessMaximum = brightnessMaximum;
         this.highBrightnessMode = highBrightnessMode;
+        this.highBrightnessTransitionPoint = highBrightnessTransitionPoint;
     }
 
     /**
@@ -103,9 +118,11 @@
     @Override
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeFloat(brightness);
+        dest.writeFloat(adjustedBrightness);
         dest.writeFloat(brightnessMinimum);
         dest.writeFloat(brightnessMaximum);
         dest.writeInt(highBrightnessMode);
+        dest.writeFloat(highBrightnessTransitionPoint);
     }
 
     public static final @android.annotation.NonNull Creator<BrightnessInfo> CREATOR =
@@ -123,9 +140,11 @@
 
     private BrightnessInfo(Parcel source) {
         brightness = source.readFloat();
+        adjustedBrightness = source.readFloat();
         brightnessMinimum = source.readFloat();
         brightnessMaximum = source.readFloat();
         highBrightnessMode = source.readInt();
+        highBrightnessTransitionPoint = source.readFloat();
     }
 
 }
diff --git a/core/res/res/values-mcc334-mnc020-as/strings.xml b/core/res/res/values-mcc334-mnc020-as/strings.xml
index 25b074e..43f5fb1 100644
--- a/core/res/res/values-mcc334-mnc020-as/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-as/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"বিশ্বাসযোগ্যতা প্ৰমাণীকৰণ বিফল হৈছে -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"সেৱাটো ছাবস্ক্ৰাইব কৰা নাই -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"এটা APNৰ বাবে একাধিক PDN সংযোগৰ অনুমতি নাই -55-"</string>
 </resources>
diff --git a/core/res/res/values-mcc334-mnc020-bn/strings.xml b/core/res/res/values-mcc334-mnc020-bn/strings.xml
index 25b074e..f58aea7 100644
--- a/core/res/res/values-mcc334-mnc020-bn/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-bn/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"যাচাই করা যায়নি -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"পরিষেবা সাবস্ক্রাইব করা হয়নি -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"নির্দিষ্ট কোনও APN-এর জন্য একাধিক PDN কানেকশন অনুমোদিত নয় -55-"</string>
 </resources>
diff --git a/core/res/res/values-mcc334-mnc020-fr-rCA/strings.xml b/core/res/res/values-mcc334-mnc020-fr-rCA/strings.xml
index 25b074e..19794da 100644
--- a/core/res/res/values-mcc334-mnc020-fr-rCA/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-fr-rCA/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"ÉCHEC DE L\'AUTHENTIFICATION -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"NON ABONNÉ AU SERVICE -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"Connexions PDN multiples interdites pour un APN donné -55-"</string>
 </resources>
diff --git a/core/res/res/values-mcc334-mnc020-gu/strings.xml b/core/res/res/values-mcc334-mnc020-gu/strings.xml
index 25b074e..5faef6f 100644
--- a/core/res/res/values-mcc334-mnc020-gu/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-gu/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"પ્રમાણીકરણ નિષ્ફળ થયું -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"સેવા સબ્સ્ક્રાઇબ કરી નથી -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"આપેલા APN માટે એક કરતાં વધારે PDN કનેક્શનની મંજૂરી નથી -55-"</string>
 </resources>
diff --git a/core/res/res/values-mcc334-mnc020-ur/strings.xml b/core/res/res/values-mcc334-mnc020-ur/strings.xml
index 25b074e..bab5589 100644
--- a/core/res/res/values-mcc334-mnc020-ur/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-ur/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"توثیق کی ناکامی -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"سروس کو سبسکرائب نہیں کیا -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"‏ایک دیئے گئے APN کے لیے متعدد PDN کنکشنز کی اجازت نہیں ہے -55-"</string>
 </resources>
diff --git a/core/res/res/values-mcc334-mnc020-zh-rCN/strings.xml b/core/res/res/values-mcc334-mnc020-zh-rCN/strings.xml
index 25b074e..a8fbe74c 100644
--- a/core/res/res/values-mcc334-mnc020-zh-rCN/strings.xml
+++ b/core/res/res/values-mcc334-mnc020-zh-rCN/strings.xml
@@ -20,10 +20,7 @@
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     <string name="config_pdp_reject_dialog_title" msgid="41208110171880430"></string>
-    <!-- no translation found for config_pdp_reject_user_authentication_failed (4683454131283459978) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_service_not_subscribed (9021140729932308119) -->
-    <skip />
-    <!-- no translation found for config_pdp_reject_multi_conn_to_same_pdn_not_allowed (3838388706348367865) -->
-    <skip />
+    <string name="config_pdp_reject_user_authentication_failed" msgid="4683454131283459978">"身份验证失败 -29-"</string>
+    <string name="config_pdp_reject_service_not_subscribed" msgid="9021140729932308119">"未订阅服务 -33-"</string>
+    <string name="config_pdp_reject_multi_conn_to_same_pdn_not_allowed" msgid="3838388706348367865">"指定的 APN 不能有多个 PDN 连接 -55-"</string>
 </resources>
diff --git a/packages/SettingsLib/res/values-eu/strings.xml b/packages/SettingsLib/res/values-eu/strings.xml
index a7f5eac5..de97437 100644
--- a/packages/SettingsLib/res/values-eu/strings.xml
+++ b/packages/SettingsLib/res/values-eu/strings.xml
@@ -304,7 +304,7 @@
     <string name="adb_warning_message" msgid="8145270656419669221">"USB bidezko arazketa garapen-xedeetarako soilik dago diseinatuta. Erabil ezazu ordenagailuaren eta gailuaren artean datuak kopiatzeko, aplikazioak gailuan jakinarazi gabe instalatzeko eta erregistro-datuak irakurtzeko."</string>
     <string name="adbwifi_warning_title" msgid="727104571653031865">"Hari gabeko arazketa baimendu nahi duzu?"</string>
     <string name="adbwifi_warning_message" msgid="8005936574322702388">"Hari gabeko arazketa garapen-xedeetarako soilik dago diseinatuta. Erabil ezazu ordenagailuaren eta gailuaren artean datuak kopiatzeko, gailuan aplikazioak jakinarazi gabe instalatzeko eta erregistroko datuak irakurtzeko."</string>
-    <string name="adb_keys_warning_message" msgid="2968555274488101220">"Aurretik baimendutako ordenagailu guztiei USB bidezko arazketarako sarbidea baliogabetu nahi diezu?"</string>
+    <string name="adb_keys_warning_message" msgid="2968555274488101220">"Aurretik baimendutako ordenagailu guztiei USB bidezko arazketarako sarbidea kendu nahi diezu?"</string>
     <string name="dev_settings_warning_title" msgid="8251234890169074553">"Baimendu garapenerako ezarpenak?"</string>
     <string name="dev_settings_warning_message" msgid="37741686486073668">"Ezarpen hauek garapen-xedeetarako pentsatu dira soilik. Baliteke ezarpenen eraginez gailua matxuratzea edo funtzionamendu okerra izatea."</string>
     <string name="verify_apps_over_usb_title" msgid="6031809675604442636">"Egiaztatu USB bidezko aplik."</string>
diff --git a/packages/SettingsLib/res/values-ky/strings.xml b/packages/SettingsLib/res/values-ky/strings.xml
index 7387985..29510a7 100644
--- a/packages/SettingsLib/res/values-ky/strings.xml
+++ b/packages/SettingsLib/res/values-ky/strings.xml
@@ -305,7 +305,7 @@
     <string name="adbwifi_warning_title" msgid="727104571653031865">"Мүчүлүштүктөрдү Wi-Fi аркылуу оңдоого уруксат бересизби?"</string>
     <string name="adbwifi_warning_message" msgid="8005936574322702388">"Мүчүлүштүктөрдү Wi-Fi аркылуу аныктоо – өндүрүү максатында гана түзүлгөн. Аны компьютериңиз менен түзмөгүңүздүн ортосунда маалыматты алмашуу, колдонмолорду түзмөгүңүзгө эскертүүсүз орнотуу жана маалыматтар таржымалын окуу үчүн колдонсоңуз болот."</string>
     <string name="adb_keys_warning_message" msgid="2968555274488101220">"Сиз мурун USB жөндөөлөрүнө уруксат берген бардык компүтерлердин жеткиси жокко чыгарылсынбы?"</string>
-    <string name="dev_settings_warning_title" msgid="8251234890169074553">"Жөндөөлөрдү өзгөртүү"</string>
+    <string name="dev_settings_warning_title" msgid="8251234890169074553">"Параметрлерди өзгөртүү"</string>
     <string name="dev_settings_warning_message" msgid="37741686486073668">"Бул орнотуулар өндүрүүчүлөр үчүн гана берилген. Булар түзмөгүңүздүн колдонмолорун бузулушуна же туура эмес иштешине алып келиши мүмкүн."</string>
     <string name="verify_apps_over_usb_title" msgid="6031809675604442636">"Орнотулуучу колдонмону текшерүү"</string>
     <string name="verify_apps_over_usb_summary" msgid="1317933737581167839">"ADB/ADT аркылуу орнотулган колдонмолордун коопсуздугу текшерилет."</string>
diff --git a/services/core/java/com/android/server/display/DisplayModeDirector.java b/services/core/java/com/android/server/display/DisplayModeDirector.java
index 5fc301e..0a22f2f 100644
--- a/services/core/java/com/android/server/display/DisplayModeDirector.java
+++ b/services/core/java/com/android/server/display/DisplayModeDirector.java
@@ -17,6 +17,7 @@
 package com.android.server.display;
 
 import static android.hardware.display.DisplayManagerInternal.REFRESH_RATE_LIMIT_HIGH_BRIGHTNESS_MODE;
+import static android.os.PowerManager.BRIGHTNESS_INVALID;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -40,6 +41,7 @@
 import android.os.IThermalService;
 import android.os.Looper;
 import android.os.Message;
+import android.os.PowerManager;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.SystemClock;
@@ -60,6 +62,7 @@
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.display.BrightnessSynchronizer;
 import com.android.internal.os.BackgroundThread;
 import com.android.server.LocalServices;
 import com.android.server.display.utils.AmbientFilter;
@@ -155,7 +158,7 @@
         mAppRequestObserver = new AppRequestObserver();
         mSettingsObserver = new SettingsObserver(context, handler);
         mDisplayObserver = new DisplayObserver(context, handler);
-        mBrightnessObserver = new BrightnessObserver(context, handler);
+        mBrightnessObserver = new BrightnessObserver(context, handler, injector);
         mUdfpsObserver = new UdfpsObserver();
         final BallotBox ballotBox = (displayId, priority, vote) -> {
             synchronized (mLock) {
@@ -1427,8 +1430,6 @@
         @Override
         public void onDisplayChanged(int displayId) {
             updateDisplayModes(displayId);
-            // TODO: Break the coupling between DisplayObserver and BrightnessObserver.
-            mBrightnessObserver.onDisplayChanged(displayId);
         }
 
         private void updateDisplayModes(int displayId) {
@@ -1465,7 +1466,7 @@
      * {@link R.array#config_ambientThresholdsOfPeakRefreshRate}.
      */
     @VisibleForTesting
-    public class BrightnessObserver extends ContentObserver {
+    public class BrightnessObserver implements DisplayManager.DisplayListener {
         private final static int LIGHT_SENSOR_RATE_MS = 250;
         private int[] mLowDisplayBrightnessThresholds;
         private int[] mLowAmbientBrightnessThresholds;
@@ -1488,6 +1489,8 @@
         private int mBrightness = -1;
 
         private final Context mContext;
+        private final Injector mInjector;
+        private final Handler mHandler;
 
         // Enable light sensor only when mShouldObserveAmbientLowChange is true or
         // mShouldObserveAmbientHighChange is true, screen is on, peak refresh rate
@@ -1500,9 +1503,11 @@
         private int mRefreshRateInLowZone;
         private int mRefreshRateInHighZone;
 
-        BrightnessObserver(Context context, Handler handler) {
-            super(handler);
+        BrightnessObserver(Context context, Handler handler, Injector injector) {
             mContext = context;
+            mHandler = handler;
+            mInjector = injector;
+
             mLowDisplayBrightnessThresholds = context.getResources().getIntArray(
                     R.array.config_brightnessThresholdsOfPeakRefreshRate);
             mLowAmbientBrightnessThresholds = context.getResources().getIntArray(
@@ -1569,8 +1574,7 @@
         public void observe(SensorManager sensorManager) {
             mSensorManager = sensorManager;
             final ContentResolver cr = mContext.getContentResolver();
-            mBrightness = Settings.System.getIntForUser(cr,
-                    Settings.System.SCREEN_BRIGHTNESS, -1 /*default*/, cr.getUserId());
+            mBrightness = getBrightness(Display.DEFAULT_DISPLAY);
 
             // DeviceConfig is accessible after system ready.
             int[] lowDisplayBrightnessThresholds =
@@ -1603,6 +1607,10 @@
 
             restartObserver();
             mDeviceConfigDisplaySettings.startListening();
+
+            mInjector.registerDisplayListener(this, mHandler,
+                    DisplayManager.EVENT_FLAG_DISPLAY_CHANGED |
+                    DisplayManager.EVENT_FLAG_DISPLAY_BRIGHTNESS);
         }
 
         public void setLoggingEnabled(boolean loggingEnabled) {
@@ -1718,28 +1726,30 @@
             }
         }
 
+        @Override
+        public void onDisplayAdded(int displayId) {}
+
+        @Override
+        public void onDisplayRemoved(int displayId) {}
+
+        @Override
         public void onDisplayChanged(int displayId) {
             if (displayId == Display.DEFAULT_DISPLAY) {
                 updateDefaultDisplayState();
-            }
-        }
 
-        @Override
-        public void onChange(boolean selfChange, Uri uri, int userId) {
-            synchronized (mLock) {
-                final ContentResolver cr = mContext.getContentResolver();
-                int brightness = Settings.System.getIntForUser(cr,
-                        Settings.System.SCREEN_BRIGHTNESS, -1 /*default*/, cr.getUserId());
-                if (brightness != mBrightness) {
-                    mBrightness = brightness;
-                    onBrightnessChangedLocked();
+                // We don't support multiple display blocking zones yet, so only handle
+                // brightness changes for the default display for now.
+                int brightness = getBrightness(displayId);
+                synchronized (mLock) {
+                    if (brightness != mBrightness) {
+                        mBrightness = brightness;
+                        onBrightnessChangedLocked();
+                    }
                 }
             }
         }
 
         private void restartObserver() {
-            final ContentResolver cr = mContext.getContentResolver();
-
             if (mRefreshRateInLowZone > 0) {
                 mShouldObserveDisplayLowChange = hasValidThreshold(
                         mLowDisplayBrightnessThresholds);
@@ -1760,15 +1770,6 @@
                 mShouldObserveAmbientHighChange = false;
             }
 
-            if (mShouldObserveDisplayLowChange || mShouldObserveDisplayHighChange) {
-                // Content Service does not check if an listener has already been registered.
-                // To ensure only one listener is registered, force an unregistration first.
-                mInjector.unregisterBrightnessObserver(cr, this);
-                mInjector.registerBrightnessObserver(cr, this);
-            } else {
-                mInjector.unregisterBrightnessObserver(cr, this);
-            }
-
             if (mShouldObserveAmbientLowChange || mShouldObserveAmbientHighChange) {
                 Resources resources = mContext.getResources();
                 String lightSensorType = resources.getString(
@@ -1968,6 +1969,15 @@
             return mDefaultDisplayState == Display.STATE_ON;
         }
 
+        private int getBrightness(int displayId) {
+            final BrightnessInfo info = mInjector.getBrightnessInfo(displayId);
+            if (info != null) {
+                return BrightnessSynchronizer.brightnessFloatToInt(info.adjustedBrightness);
+            }
+
+            return BRIGHTNESS_INVALID;
+        }
+
         private final class LightSensorEventListener implements SensorEventListener {
             final private static int INJECT_EVENTS_INTERVAL_MS = LIGHT_SENSOR_RATE_MS;
             private float mLastSensorData;
@@ -2283,6 +2293,7 @@
         private final BallotBox mBallotBox;
         private final Handler mHandler;
         private final SparseIntArray mHbmMode = new SparseIntArray();
+        private final SparseBooleanArray mHbmActive = new SparseBooleanArray();
         private final Injector mInjector;
         private final DeviceConfigDisplaySettings mDeviceConfigDisplaySettings;
         private int mRefreshRateInHbmSunlight;
@@ -2351,6 +2362,7 @@
         public void onDisplayRemoved(int displayId) {
             mBallotBox.vote(displayId, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE, null);
             mHbmMode.delete(displayId);
+            mHbmActive.delete(displayId);
         }
 
         @Override
@@ -2360,12 +2372,17 @@
                 // Display no longer there. Assume we'll get an onDisplayRemoved very soon.
                 return;
             }
+
             final int hbmMode = info.highBrightnessMode;
-            if (hbmMode == mHbmMode.get(displayId)) {
+            final boolean isHbmActive = hbmMode != BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF &&
+                info.adjustedBrightness > info.highBrightnessTransitionPoint;
+            if (hbmMode == mHbmMode.get(displayId) &&
+                isHbmActive == mHbmActive.get(displayId)) {
                 // no change, ignore.
                 return;
             }
             mHbmMode.put(displayId, hbmMode);
+            mHbmActive.put(displayId, isHbmActive);
             recalculateVotesForDisplay(displayId);
         }
 
@@ -2379,28 +2396,36 @@
         }
 
         private void recalculateVotesForDisplay(int displayId) {
-            final int hbmMode = mHbmMode.get(displayId, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF);
             Vote vote = null;
-            if (hbmMode == BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT) {
-                // Device resource properties take priority over DisplayDeviceConfig
-                if (mRefreshRateInHbmSunlight > 0) {
-                    vote = Vote.forRefreshRates(mRefreshRateInHbmSunlight,
-                            mRefreshRateInHbmSunlight);
-                } else {
-                    final List<RefreshRateLimitation> limits =
-                        mDisplayManagerInternal.getRefreshRateLimitations(displayId);
-                    for (int i = 0; limits != null && i < limits.size(); i++) {
-                        final RefreshRateLimitation limitation = limits.get(i);
-                        if (limitation.type == REFRESH_RATE_LIMIT_HIGH_BRIGHTNESS_MODE) {
-                            vote = Vote.forRefreshRates(limitation.range.min, limitation.range.max);
-                            break;
+            if (mHbmActive.get(displayId, false)) {
+                final int hbmMode =
+                    mHbmMode.get(displayId, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF);
+                if (hbmMode == BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT) {
+                    // Device resource properties take priority over DisplayDeviceConfig
+                    if (mRefreshRateInHbmSunlight > 0) {
+                        vote = Vote.forRefreshRates(mRefreshRateInHbmSunlight,
+                                mRefreshRateInHbmSunlight);
+                    } else {
+                        final List<RefreshRateLimitation> limits =
+                            mDisplayManagerInternal.getRefreshRateLimitations(displayId);
+                        for (int i = 0; limits != null && i < limits.size(); i++) {
+                            final RefreshRateLimitation limitation = limits.get(i);
+                            if (limitation.type == REFRESH_RATE_LIMIT_HIGH_BRIGHTNESS_MODE) {
+                                vote = Vote.forRefreshRates(limitation.range.min,
+                                        limitation.range.max);
+                                break;
+                            }
                         }
                     }
+                } else if (hbmMode == BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR &&
+                        mRefreshRateInHbmHdr > 0) {
+                    // HBM for HDR vote isn't supported through DisplayDeviceConfig yet, so look for
+                    // a vote from Device properties
+                    vote = Vote.forRefreshRates(mRefreshRateInHbmHdr, mRefreshRateInHbmHdr);
+                } else {
+                    Slog.w(TAG, "Unexpected HBM mode " + hbmMode + " for display ID " + displayId);
                 }
-            }
-            if (hbmMode == BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR
-                    && mRefreshRateInHbmHdr > 0) {
-                vote = Vote.forRefreshRates(mRefreshRateInHbmHdr, mRefreshRateInHbmHdr);
+
             }
             mBallotBox.vote(displayId, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE, vote);
         }
@@ -2408,6 +2433,7 @@
         void dumpLocked(PrintWriter pw) {
             pw.println("   HbmObserver");
             pw.println("     mHbmMode: " + mHbmMode);
+            pw.println("     mHbmActive: " + mHbmActive);
             pw.println("     mRefreshRateInHbmSunlight: " + mRefreshRateInHbmSunlight);
             pw.println("     mRefreshRateInHbmHdr: " + mRefreshRateInHbmHdr);
         }
@@ -2630,19 +2656,11 @@
     }
 
     interface Injector {
-        // TODO: brightnessfloat: change this to the float setting
-        Uri DISPLAY_BRIGHTNESS_URI = Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS);
         Uri PEAK_REFRESH_RATE_URI = Settings.System.getUriFor(Settings.System.PEAK_REFRESH_RATE);
 
         @NonNull
         DeviceConfigInterface getDeviceConfig();
 
-        void registerBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer);
-
-        void unregisterBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer);
-
         void registerPeakRefreshRateObserver(@NonNull ContentResolver cr,
                 @NonNull ContentObserver observer);
 
@@ -2672,19 +2690,6 @@
         }
 
         @Override
-        public void registerBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer) {
-            cr.registerContentObserver(DISPLAY_BRIGHTNESS_URI, false /*notifyDescendants*/,
-                    observer, UserHandle.USER_SYSTEM);
-        }
-
-        @Override
-        public void unregisterBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer) {
-            cr.unregisterContentObserver(observer);
-        }
-
-        @Override
         public void registerPeakRefreshRateObserver(@NonNull ContentResolver cr,
                 @NonNull ContentObserver observer) {
             cr.registerContentObserver(PEAK_REFRESH_RATE_URI, false /*notifyDescendants*/,
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index abbe13a..34b635b 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -1259,10 +1259,6 @@
             putScreenBrightnessSetting(brightnessState, /* updateCurrent */ true);
         }
 
-        // We save the brightness info *after* the brightness setting has been changed so that
-        // the brightness info reflects the latest value.
-        saveBrightnessInfo(getScreenBrightnessSetting());
-
         // Apply dimming by at least some minimum amount when user activity
         // timeout is about to expire.
         if (mPowerRequest.policy == DisplayPowerRequest.POLICY_DIM) {
@@ -1393,6 +1389,11 @@
                         hadUserBrightnessPoint);
             }
 
+            // We save the brightness info *after* the brightness setting has been changed and
+            // adjustments made so that the brightness info reflects the latest value.
+            saveBrightnessInfo(getScreenBrightnessSetting(), animateValue);
+        } else {
+            saveBrightnessInfo(getScreenBrightnessSetting());
         }
 
         // Log any changes to what is currently driving the brightness setting.
@@ -1509,18 +1510,27 @@
         synchronized (mCachedBrightnessInfo) {
             return new BrightnessInfo(
                     mCachedBrightnessInfo.brightness,
+                    mCachedBrightnessInfo.adjustedBrightness,
                     mCachedBrightnessInfo.brightnessMin,
                     mCachedBrightnessInfo.brightnessMax,
-                    mCachedBrightnessInfo.hbmMode);
+                    mCachedBrightnessInfo.hbmMode,
+                    mCachedBrightnessInfo.highBrightnessTransitionPoint);
         }
     }
 
     private void saveBrightnessInfo(float brightness) {
+        saveBrightnessInfo(brightness, brightness);
+    }
+
+    private void saveBrightnessInfo(float brightness, float adjustedBrightness) {
         synchronized (mCachedBrightnessInfo) {
             mCachedBrightnessInfo.brightness = brightness;
+            mCachedBrightnessInfo.adjustedBrightness = adjustedBrightness;
             mCachedBrightnessInfo.brightnessMin = mHbmController.getCurrentBrightnessMin();
             mCachedBrightnessInfo.brightnessMax = mHbmController.getCurrentBrightnessMax();
             mCachedBrightnessInfo.hbmMode = mHbmController.getHighBrightnessMode();
+            mCachedBrightnessInfo.highBrightnessTransitionPoint =
+                mHbmController.getTransitionPoint();
         }
     }
 
@@ -2195,6 +2205,18 @@
         pw.println("  mSkipScreenOnBrightnessRamp=" + mSkipScreenOnBrightnessRamp);
         pw.println("  mColorFadeFadesConfig=" + mColorFadeFadesConfig);
         pw.println("  mColorFadeEnabled=" + mColorFadeEnabled);
+        synchronized (mCachedBrightnessInfo) {
+            pw.println("  mCachedBrightnessInfo.brightness=" + mCachedBrightnessInfo.brightness);
+            pw.println("  mCachedBrightnessInfo.adjustedBrightness=" +
+                    mCachedBrightnessInfo.adjustedBrightness);
+            pw.println("  mCachedBrightnessInfo.brightnessMin=" +
+                    mCachedBrightnessInfo.brightnessMin);
+            pw.println("  mCachedBrightnessInfo.brightnessMax=" +
+                    mCachedBrightnessInfo.brightnessMax);
+            pw.println("  mCachedBrightnessInfo.hbmMode=" + mCachedBrightnessInfo.hbmMode);
+            pw.println("  mCachedBrightnessInfo.highBrightnessTransitionPoint=" +
+                    mCachedBrightnessInfo.highBrightnessTransitionPoint);
+        }
         pw.println("  mDisplayBlanksAfterDozeConfig=" + mDisplayBlanksAfterDozeConfig);
         pw.println("  mBrightnessBucketsInDozeConfig=" + mBrightnessBucketsInDozeConfig);
 
@@ -2606,8 +2628,10 @@
 
     static class CachedBrightnessInfo {
         public float brightness;
+        public float adjustedBrightness;
         public float brightnessMin;
         public float brightnessMax;
         public int hbmMode;
+        public float highBrightnessTransitionPoint;
     }
 }
diff --git a/services/core/java/com/android/server/display/HighBrightnessModeController.java b/services/core/java/com/android/server/display/HighBrightnessModeController.java
index 2791f6a..1e1cfeb 100644
--- a/services/core/java/com/android/server/display/HighBrightnessModeController.java
+++ b/services/core/java/com/android/server/display/HighBrightnessModeController.java
@@ -59,6 +59,9 @@
 
     private static final float HDR_PERCENT_OF_SCREEN_REQUIRED = 0.50f;
 
+    @VisibleForTesting
+    static final float HBM_TRANSITION_POINT_INVALID = Float.POSITIVE_INFINITY;
+
     private final float mBrightnessMin;
     private final float mBrightnessMax;
     private final Handler mHandler;
@@ -214,6 +217,14 @@
         return mHbmMode;
     }
 
+    float getTransitionPoint() {
+        if (deviceSupportsHbm()) {
+            return mHbmData.transitionPoint;
+        } else {
+            return HBM_TRANSITION_POINT_INVALID;
+        }
+    }
+
     void stop() {
         registerHdrListener(null /*displayToken*/);
         mSkinThermalStatusObserver.stopObserving();
diff --git a/services/tests/servicestests/src/com/android/server/display/DisplayModeDirectorTest.java b/services/tests/servicestests/src/com/android/server/display/DisplayModeDirectorTest.java
index 0dd5c61..418831f 100644
--- a/services/tests/servicestests/src/com/android/server/display/DisplayModeDirectorTest.java
+++ b/services/tests/servicestests/src/com/android/server/display/DisplayModeDirectorTest.java
@@ -26,6 +26,7 @@
 import static android.hardware.display.DisplayManager.DeviceConfig.KEY_REFRESH_RATE_IN_LOW_ZONE;
 
 import static com.android.server.display.DisplayModeDirector.Vote.INVALID_SIZE;
+import static com.android.server.display.HighBrightnessModeController.HBM_TRANSITION_POINT_INVALID;
 
 import static com.google.common.truth.Truth.assertThat;
 
@@ -74,6 +75,7 @@
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.internal.display.BrightnessSynchronizer;
 import com.android.internal.util.Preconditions;
 import com.android.internal.util.test.FakeSettingsProvider;
 import com.android.internal.util.test.FakeSettingsProviderRule;
@@ -110,6 +112,7 @@
     private static final boolean DEBUG = false;
     private static final float FLOAT_TOLERANCE = 0.01f;
     private static final int DISPLAY_ID = 0;
+    private static final float TRANSITION_POINT = 0.763f;
 
     private Context mContext;
     private FakesInjector mInjector;
@@ -751,19 +754,27 @@
 
         director.start(sensorManager);
 
-        ArgumentCaptor<SensorEventListener> listenerCaptor =
+        ArgumentCaptor<DisplayListener> displayListenerCaptor =
+                  ArgumentCaptor.forClass(DisplayListener.class);
+        verify(mInjector).registerDisplayListener(displayListenerCaptor.capture(),
+                any(Handler.class),
+                eq(DisplayManager.EVENT_FLAG_DISPLAY_CHANGED
+                    | DisplayManager.EVENT_FLAG_DISPLAY_BRIGHTNESS));
+        DisplayListener displayListener = displayListenerCaptor.getValue();
+
+        ArgumentCaptor<SensorEventListener> sensorListenerCaptor =
                 ArgumentCaptor.forClass(SensorEventListener.class);
         Mockito.verify(sensorManager, Mockito.timeout(TimeUnit.SECONDS.toMillis(1)))
                 .registerListener(
-                        listenerCaptor.capture(),
+                        sensorListenerCaptor.capture(),
                         eq(lightSensor),
                         anyInt(),
                         any(Handler.class));
-        SensorEventListener listener = listenerCaptor.getValue();
+        SensorEventListener sensorListener = sensorListenerCaptor.getValue();
 
-        setBrightness(10);
+        setBrightness(10, 10, displayListener);
         // Sensor reads 20 lux,
-        listener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 20 /*lux*/));
+        sensorListener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 20 /*lux*/));
 
         Vote vote = director.getVote(Display.DEFAULT_DISPLAY, Vote.PRIORITY_FLICKER_REFRESH_RATE);
         assertVoteForRefreshRate(vote, 90 /*fps*/);
@@ -771,9 +782,11 @@
         assertThat(vote).isNotNull();
         assertThat(vote.disableRefreshRateSwitching).isTrue();
 
-        setBrightness(125);
+        // We expect DisplayModeDirector to act on BrightnessInfo.adjustedBrightness; set only this
+        // parameter to the necessary threshold
+        setBrightness(10, 125, displayListener);
         // Sensor reads 1000 lux,
-        listener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 1000 /*lux*/));
+        sensorListener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 1000 /*lux*/));
 
         vote = director.getVote(Display.DEFAULT_DISPLAY, Vote.PRIORITY_FLICKER_REFRESH_RATE);
         assertThat(vote).isNull();
@@ -799,6 +812,14 @@
 
         director.start(sensorManager);
 
+        ArgumentCaptor<DisplayListener> displayListenerCaptor =
+                  ArgumentCaptor.forClass(DisplayListener.class);
+        verify(mInjector).registerDisplayListener(displayListenerCaptor.capture(),
+                any(Handler.class),
+                eq(DisplayManager.EVENT_FLAG_DISPLAY_CHANGED
+                    | DisplayManager.EVENT_FLAG_DISPLAY_BRIGHTNESS));
+        DisplayListener displayListener = displayListenerCaptor.getValue();
+
         ArgumentCaptor<SensorEventListener> listenerCaptor =
                 ArgumentCaptor.forClass(SensorEventListener.class);
         verify(sensorManager, Mockito.timeout(TimeUnit.SECONDS.toMillis(1)))
@@ -807,20 +828,22 @@
                         eq(lightSensor),
                         anyInt(),
                         any(Handler.class));
-        SensorEventListener listener = listenerCaptor.getValue();
+        SensorEventListener sensorListener = listenerCaptor.getValue();
 
-        setBrightness(100);
+        setBrightness(100, 100, displayListener);
         // Sensor reads 2000 lux,
-        listener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 2000));
+        sensorListener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 2000));
 
         Vote vote = director.getVote(Display.DEFAULT_DISPLAY, Vote.PRIORITY_FLICKER_REFRESH_RATE);
         assertThat(vote).isNull();
         vote = director.getVote(Display.DEFAULT_DISPLAY, Vote.PRIORITY_FLICKER_REFRESH_RATE_SWITCH);
         assertThat(vote).isNull();
 
-        setBrightness(255);
+        // We expect DisplayModeDirector to act on BrightnessInfo.adjustedBrightness; set only this
+        // parameter to the necessary threshold
+        setBrightness(100, 255, displayListener);
         // Sensor reads 9000 lux,
-        listener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 9000));
+        sensorListener.onSensorChanged(TestUtils.createSensorEvent(lightSensor, 9000));
 
         vote = director.getVote(Display.DEFAULT_DISPLAY, Vote.PRIORITY_FLICKER_REFRESH_RATE);
         assertVoteForRefreshRate(vote, 60 /*fps*/);
@@ -1435,16 +1458,58 @@
         Vote vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
 
-        // Turn on HBM
+        // Turn on HBM, with brightness in the HBM range
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(0.45f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR));
+                new BrightnessInfo(TRANSITION_POINT + FLOAT_TOLERANCE, 0.0f, 1.0f,
+                    BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR, TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertVoteForRefreshRate(vote, hbmRefreshRate);
+
+        // Turn on HBM, with brightness below the HBM range
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(TRANSITION_POINT - FLOAT_TOLERANCE, 0.0f, 1.0f,
+                    BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR, TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn off HBM
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(0.45f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn on HBM, with brightness in the HBM range
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(TRANSITION_POINT + FLOAT_TOLERANCE, 0.0f, 1.0f,
+                    BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR, TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertVoteForRefreshRate(vote, hbmRefreshRate);
 
         // Turn off HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(0.45f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF));
+                new BrightnessInfo(0.45f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn on HBM, with brightness below the HBM range
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(TRANSITION_POINT - FLOAT_TOLERANCE, 0.0f, 1.0f,
+                    BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR, TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn off HBM
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(0.45f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
@@ -1514,7 +1579,8 @@
 
         // Turn on HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT));
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertVoteForRefreshRate(vote, initialRefreshRate);
@@ -1531,14 +1597,16 @@
 
         // Turn off HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF));
+                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
 
         // Turn HBM on again and ensure the updated vote value stuck
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT));
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertVoteForRefreshRate(vote, updatedRefreshRate);
@@ -1553,7 +1621,8 @@
 
         // Turn off HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF));
+                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
@@ -1584,14 +1653,82 @@
 
         // Turn on HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT));
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
 
         // Turn off HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF));
+                new BrightnessInfo(0.43f, 0.1f, 0.8f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+    }
+
+    @Test
+    public void testHbmVoting_HbmUnsupported() {
+        DisplayModeDirector director =
+                createDirectorFromRefreshRateArray(new float[] {60.0f, 90.0f}, 0);
+        director.start(createMockSensorManager());
+
+        ArgumentCaptor<DisplayListener> captor =
+                  ArgumentCaptor.forClass(DisplayListener.class);
+        verify(mInjector).registerDisplayListener(captor.capture(), any(Handler.class),
+                  eq(DisplayManager.EVENT_FLAG_DISPLAY_BRIGHTNESS
+                  | DisplayManager.EVENT_FLAG_DISPLAY_REMOVED));
+        DisplayListener listener = captor.getValue();
+
+        // Specify Limitation
+        when(mDisplayManagerInternalMock.getRefreshRateLimitations(DISPLAY_ID)).thenReturn(
+                List.of(new RefreshRateLimitation(
+                        DisplayManagerInternal.REFRESH_RATE_LIMIT_HIGH_BRIGHTNESS_MODE,
+                        60.0f, 60.0f)));
+
+        // Verify that there is no HBM vote initially
+        Vote vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn on HBM when HBM is supported; expect a valid transition point and a vote.
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertVoteForRefreshRate(vote, 60.0f);
+
+        // Turn off HBM
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn on Sunlight HBM when HBM is unsupported; expect an invalid transition point and
+        // no vote.
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    HBM_TRANSITION_POINT_INVALID));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn on HDR HBM when HBM is unsupported; expect an invalid transition point and
+        // no vote.
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_HDR,
+                    HBM_TRANSITION_POINT_INVALID));
+        listener.onDisplayChanged(DISPLAY_ID);
+        vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
+        assertNull(vote);
+
+        // Turn off HBM
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertNull(vote);
@@ -1600,7 +1737,7 @@
     private void setHbmAndAssertRefreshRate(
             DisplayModeDirector director, DisplayListener listener, int mode, float rr) {
         when(mInjector.getBrightnessInfo(DISPLAY_ID))
-                .thenReturn(new BrightnessInfo(1.0f, 0.0f, 1.0f, mode));
+                .thenReturn(new BrightnessInfo(1.0f, 0.0f, 1.0f, mode, TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
 
         final Vote vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
@@ -1679,7 +1816,8 @@
 
         // Turn on HBM
         when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
-                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT));
+                new BrightnessInfo(1.0f, 0.0f, 1.0f, BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT,
+                    TRANSITION_POINT));
         listener.onDisplayChanged(DISPLAY_ID);
         vote = director.getVote(DISPLAY_ID, Vote.PRIORITY_HIGH_BRIGHTNESS_MODE);
         assertVoteForRefreshRate(vote, 60.f);
@@ -1834,11 +1972,14 @@
         }
     }
 
-    private void setBrightness(int brightness) {
-        Settings.System.putInt(mContext.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS,
-                brightness);
-        mInjector.notifyBrightnessChanged();
-        waitForIdleSync();
+    private void setBrightness(int brightness, int adjustedBrightness, DisplayListener listener) {
+        float floatBri = BrightnessSynchronizer.brightnessIntToFloat(brightness);
+        float floatAdjBri = BrightnessSynchronizer.brightnessIntToFloat(adjustedBrightness);
+
+        when(mInjector.getBrightnessInfo(DISPLAY_ID)).thenReturn(
+                new BrightnessInfo(floatBri, floatAdjBri, 0.0f, 1.0f,
+                    BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF, TRANSITION_POINT));
+        listener.onDisplayChanged(DISPLAY_ID);
     }
 
     private void setPeakRefreshRate(float fps) {
@@ -1902,27 +2043,6 @@
         }
 
         @Override
-        public void registerBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer) {
-            if (mBrightnessObserver != null) {
-                throw new IllegalStateException("Tried to register a second brightness observer");
-            }
-            mBrightnessObserver = observer;
-        }
-
-        @Override
-        public void unregisterBrightnessObserver(@NonNull ContentResolver cr,
-                @NonNull ContentObserver observer) {
-            mBrightnessObserver = null;
-        }
-
-        void notifyBrightnessChanged() {
-            if (mBrightnessObserver != null) {
-                mBrightnessObserver.dispatchChange(false /*selfChange*/, DISPLAY_BRIGHTNESS_URI);
-            }
-        }
-
-        @Override
         public void registerPeakRefreshRateObserver(@NonNull ContentResolver cr,
                 @NonNull ContentObserver observer) {
             mPeakRefreshRateObserver = observer;
diff --git a/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java b/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
index cc3591c8..aca8632 100644
--- a/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
+++ b/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
@@ -20,6 +20,8 @@
 import static android.hardware.display.BrightnessInfo.HIGH_BRIGHTNESS_MODE_OFF;
 import static android.hardware.display.BrightnessInfo.HIGH_BRIGHTNESS_MODE_SUNLIGHT;
 
+import static com.android.server.display.HighBrightnessModeController.HBM_TRANSITION_POINT_INVALID;
+
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.spy;
@@ -124,6 +126,7 @@
                 mInjectorMock, mHandler, DISPLAY_WIDTH, DISPLAY_HEIGHT, mDisplayToken, DEFAULT_MIN,
                 DEFAULT_MAX, null, () -> {}, mContextSpy);
         assertState(hbmc, DEFAULT_MIN, DEFAULT_MAX, HIGH_BRIGHTNESS_MODE_OFF);
+        assertEquals(hbmc.getTransitionPoint(), HBM_TRANSITION_POINT_INVALID, 0.0f);
     }
 
     @Test
@@ -135,6 +138,7 @@
         hbmc.setAutoBrightnessEnabled(true);
         hbmc.onAmbientLuxChange(MINIMUM_LUX - 1); // below allowed range
         assertState(hbmc, DEFAULT_MIN, DEFAULT_MAX, HIGH_BRIGHTNESS_MODE_OFF);
+        assertEquals(hbmc.getTransitionPoint(), HBM_TRANSITION_POINT_INVALID, 0.0f);
     }
 
     @Test