diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 41256b86bf065..4191ab9691d1a 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -3577,9 +3577,9 @@
          config_sidefpsSkipWaitForPowerVendorAcquireMessage -->
     <integer name="config_sidefpsSkipWaitForPowerAcquireMessage">6</integer>
 
-    <!-- This vendor acquired message that will cause the sidefpsKgPowerPress window to be skipped.
-         config_sidefpsSkipWaitForPowerOnFingerUp must be true and
-         config_sidefpsSkipWaitForPowerAcquireMessage must be BIOMETRIC_ACQUIRED_VENDOR == 6. -->
+    <!-- This vendor acquired message will cause the sidefpsKgPowerPress window to be skipped
+         when config_sidefpsSkipWaitForPowerAcquireMessage == 6 (VENDOR) and the vendor acquire
+         message equals this constant -->
     <integer name="config_sidefpsSkipWaitForPowerVendorAcquireMessage">2</integer>
 
     <!-- This config is used to force VoiceInteractionService to start on certain low ram devices.
diff --git a/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClient.java b/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClient.java
index fa751007198e9..a778b573f2258 100644
--- a/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClient.java
+++ b/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClient.java
@@ -16,6 +16,7 @@
 
 package com.android.server.biometrics.sensors.fingerprint.aidl;
 
+import static android.hardware.biometrics.BiometricFingerprintConstants.FINGERPRINT_ACQUIRED_START;
 import static android.hardware.biometrics.BiometricFingerprintConstants.FINGERPRINT_ACQUIRED_VENDOR;
 
 import android.annotation.NonNull;
@@ -57,6 +58,7 @@ import com.android.server.biometrics.sensors.SensorOverlays;
 import com.android.server.biometrics.sensors.fingerprint.PowerPressHandler;
 import com.android.server.biometrics.sensors.fingerprint.Udfps;
 
+import java.time.Clock;
 import java.util.ArrayList;
 import java.util.function.Supplier;
 
@@ -88,7 +90,9 @@ class FingerprintAuthenticationClient extends AuthenticationClient<AidlSession>
     private long mWaitForAuthKeyguard;
     private long mWaitForAuthBp;
     private long mIgnoreAuthFor;
+    private long mSideFpsLastAcquireStartTime;
     private Runnable mAuthSuccessRunnable;
+    private final Clock mClock;
 
     FingerprintAuthenticationClient(
             @NonNull Context context,
@@ -112,7 +116,8 @@ class FingerprintAuthenticationClient extends AuthenticationClient<AidlSession>
             @Nullable ISidefpsController sidefpsController,
             boolean allowBackgroundAuthentication,
             @NonNull FingerprintSensorPropertiesInternal sensorProps,
-            @NonNull Handler handler) {
+            @NonNull Handler handler,
+            @NonNull Clock clock) {
         super(
                 context,
                 lazyDaemon,
@@ -154,6 +159,8 @@ class FingerprintAuthenticationClient extends AuthenticationClient<AidlSession>
         mSkipWaitForPowerVendorAcquireMessage =
                 context.getResources().getInteger(
                         R.integer.config_sidefpsSkipWaitForPowerVendorAcquireMessage);
+        mSideFpsLastAcquireStartTime = -1;
+        mClock = clock;
 
         if (mSensorProps.isAnySidefpsType()) {
             if (Build.isDebuggable()) {
@@ -235,8 +242,14 @@ class FingerprintAuthenticationClient extends AuthenticationClient<AidlSession>
                             return;
                         }
                         delay = isKeyguard() ? mWaitForAuthKeyguard : mWaitForAuthBp;
-                        Slog.i(TAG, "(sideFPS) Auth succeeded, sideFps waiting for power for: "
-                                + delay + "ms");
+
+                        if (mSideFpsLastAcquireStartTime != -1) {
+                            delay = Math.max(0,
+                                    delay - (mClock.millis() - mSideFpsLastAcquireStartTime));
+                        }
+
+                        Slog.i(TAG, "(sideFPS) Auth succeeded, sideFps "
+                                + "waiting for power until: " + delay + "ms");
                     }
 
                     if (mHandler.hasMessages(MESSAGE_FINGER_UP)) {
@@ -260,13 +273,15 @@ class FingerprintAuthenticationClient extends AuthenticationClient<AidlSession>
         mSensorOverlays.ifUdfps(controller -> controller.onAcquired(getSensorId(), acquiredInfo));
         super.onAcquired(acquiredInfo, vendorCode);
         if (mSensorProps.isAnySidefpsType()) {
+            if (acquiredInfo == FINGERPRINT_ACQUIRED_START) {
+                mSideFpsLastAcquireStartTime = mClock.millis();
+            }
             final boolean shouldLookForVendor =
                     mSkipWaitForPowerAcquireMessage == FINGERPRINT_ACQUIRED_VENDOR;
             final boolean acquireMessageMatch = acquiredInfo == mSkipWaitForPowerAcquireMessage;
             final boolean vendorMessageMatch = vendorCode == mSkipWaitForPowerVendorAcquireMessage;
             final boolean ignorePowerPress =
-                    (acquireMessageMatch && !shouldLookForVendor) || (shouldLookForVendor
-                            && acquireMessageMatch && vendorMessageMatch);
+                    acquireMessageMatch && (!shouldLookForVendor || vendorMessageMatch);
 
             if (ignorePowerPress) {
                 Slog.d(TAG, "(sideFPS) onFingerUp");
diff --git a/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintProvider.java b/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintProvider.java
index 6f6c09b91a661..dabb2cf5819a9 100644
--- a/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintProvider.java
+++ b/services/core/java/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintProvider.java
@@ -47,6 +47,7 @@ import android.os.IBinder;
 import android.os.Looper;
 import android.os.RemoteException;
 import android.os.ServiceManager;
+import android.os.SystemClock;
 import android.os.UserManager;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -447,7 +448,8 @@ public class FingerprintProvider implements IBinder.DeathRecipient, ServiceProvi
                     mBiometricContext, isStrongBiometric,
                     mTaskStackListener, mSensors.get(sensorId).getLockoutCache(),
                     mUdfpsOverlayController, mSidefpsController, allowBackgroundAuthentication,
-                    mSensors.get(sensorId).getSensorProperties(), mHandler);
+                    mSensors.get(sensorId).getSensorProperties(), mHandler,
+                    SystemClock.elapsedRealtimeClock());
             scheduleForSensor(sensorId, client, mBiometricStateCallback);
         });
     }
diff --git a/services/tests/servicestests/src/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClientTest.java b/services/tests/servicestests/src/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClientTest.java
index a5c181d532867..606f4864643c4 100644
--- a/services/tests/servicestests/src/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClientTest.java
+++ b/services/tests/servicestests/src/com/android/server/biometrics/sensors/fingerprint/aidl/FingerprintAuthenticationClientTest.java
@@ -41,6 +41,7 @@ import android.hardware.biometrics.common.OperationContext;
 import android.hardware.biometrics.fingerprint.ISession;
 import android.hardware.biometrics.fingerprint.PointerContext;
 import android.hardware.fingerprint.Fingerprint;
+import android.hardware.fingerprint.FingerprintManager;
 import android.hardware.fingerprint.FingerprintSensorPropertiesInternal;
 import android.hardware.fingerprint.ISidefpsController;
 import android.hardware.fingerprint.IUdfpsOverlayController;
@@ -73,6 +74,7 @@ import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
 
+import java.time.Clock;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
@@ -128,6 +130,8 @@ public class FingerprintAuthenticationClientTest {
     private ICancellationSignal mCancellationSignal;
     @Mock
     private Probe mLuxProbe;
+    @Mock
+    private Clock mClock;
     @Captor
     private ArgumentCaptor<OperationContext> mOperationContextCaptor;
     @Captor
@@ -446,6 +450,52 @@ public class FingerprintAuthenticationClientTest {
         verify(mCallback).onClientFinished(any(), eq(true));
     }
 
+    @Test
+    public void sideFingerprintSkipsWindowIfVendorMessageMatch() throws Exception {
+        when(mSensorProps.isAnySidefpsType()).thenReturn(true);
+        final int vendorAcquireMessage = 1234;
+
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsSkipWaitForPowerAcquireMessage,
+                FingerprintManager.FINGERPRINT_ACQUIRED_VENDOR);
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsSkipWaitForPowerVendorAcquireMessage,
+                vendorAcquireMessage);
+
+        final FingerprintAuthenticationClient client = createClient(1);
+        client.start(mCallback);
+        mLooper.dispatchAll();
+        client.onAuthenticated(new Fingerprint("friendly", 4 /* fingerId */, 5 /* deviceId */),
+                true /* authenticated */, new ArrayList<>());
+        client.onAcquired(FingerprintManager.FINGERPRINT_ACQUIRED_VENDOR, vendorAcquireMessage);
+        mLooper.dispatchAll();
+
+        verify(mCallback).onClientFinished(any(), eq(true));
+    }
+
+    @Test
+    public void sideFingerprintDoesNotSkipWindowOnVendorErrorMismatch() throws Exception {
+        when(mSensorProps.isAnySidefpsType()).thenReturn(true);
+        final int vendorAcquireMessage = 1234;
+
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsSkipWaitForPowerAcquireMessage,
+                FingerprintManager.FINGERPRINT_ACQUIRED_VENDOR);
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsSkipWaitForPowerVendorAcquireMessage,
+                vendorAcquireMessage);
+
+        final FingerprintAuthenticationClient client = createClient(1);
+        client.start(mCallback);
+        mLooper.dispatchAll();
+        client.onAuthenticated(new Fingerprint("friendly", 4 /* fingerId */, 5 /* deviceId */),
+                true /* authenticated */, new ArrayList<>());
+        client.onAcquired(FingerprintManager.FINGERPRINT_ACQUIRED_VENDOR, 1);
+        mLooper.dispatchAll();
+
+        verify(mCallback, never()).onClientFinished(any(), anyBoolean());
+    }
+
     @Test
     public void sideFingerprintSendsAuthIfFingerUp() throws Exception {
         when(mSensorProps.isAnySidefpsType()).thenReturn(true);
@@ -493,6 +543,79 @@ public class FingerprintAuthenticationClientTest {
         verify(mCallback).onClientFinished(any(), eq(true));
     }
 
+    @Test
+    public void sideFingerprintPowerWindowStartsOnAcquireStart() throws Exception {
+        final int powerWindow = 500;
+        final long authStart = 300;
+
+        when(mSensorProps.isAnySidefpsType()).thenReturn(true);
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsBpPowerPressWindow, powerWindow);
+
+        final FingerprintAuthenticationClient client = createClient(1);
+        client.start(mCallback);
+
+        // Acquire start occurs at time = 0ms
+        when(mClock.millis()).thenReturn(0L);
+        client.onAcquired(FingerprintManager.FINGERPRINT_ACQUIRED_START, 0 /* vendorCode */);
+
+        // Auth occurs at time = 300
+        when(mClock.millis()).thenReturn(authStart);
+        // At this point the delay should be 500 - (300 - 0) == 200 milliseconds.
+        client.onAuthenticated(new Fingerprint("friendly", 4 /* fingerId */, 5 /* deviceId */),
+                true /* authenticated */, new ArrayList<>());
+        mLooper.dispatchAll();
+        verify(mCallback, never()).onClientFinished(any(), anyBoolean());
+
+        // After waiting 200 milliseconds, auth should succeed.
+        mLooper.moveTimeForward(powerWindow - authStart);
+        mLooper.dispatchAll();
+        verify(mCallback).onClientFinished(any(), eq(true));
+    }
+
+    @Test
+    public void sideFingerprintPowerWindowStartsOnLastAcquireStart() throws Exception {
+        final int powerWindow = 500;
+
+        when(mSensorProps.isAnySidefpsType()).thenReturn(true);
+        mContext.getOrCreateTestableResources().addOverride(
+                R.integer.config_sidefpsBpPowerPressWindow, powerWindow);
+
+        final FingerprintAuthenticationClient client = createClient(1);
+        client.start(mCallback);
+        // Acquire start occurs at time = 0ms
+        when(mClock.millis()).thenReturn(0L);
+        client.onAcquired(FingerprintManager.FINGERPRINT_ACQUIRED_START, 0 /* vendorCode */);
+
+        // Auth reject occurs at time = 300ms
+        when(mClock.millis()).thenReturn(300L);
+        client.onAuthenticated(new Fingerprint("friendly", 4 /* fingerId */, 5 /* deviceId */),
+                false /* authenticated */, new ArrayList<>());
+        mLooper.dispatchAll();
+
+        mLooper.moveTimeForward(300);
+        mLooper.dispatchAll();
+        verify(mCallback, never()).onClientFinished(any(), anyBoolean());
+
+        when(mClock.millis()).thenReturn(1300L);
+        client.onAcquired(FingerprintManager.FINGERPRINT_ACQUIRED_START, 0 /* vendorCode */);
+
+        // If code is correct, the new acquired start timestamp should be used
+        // and the code should only have to wait 500 - (1500-1300)ms.
+        when(mClock.millis()).thenReturn(1500L);
+        client.onAuthenticated(new Fingerprint("friendly", 4 /* fingerId */, 5 /* deviceId */),
+                true /* authenticated */, new ArrayList<>());
+        mLooper.dispatchAll();
+
+        mLooper.moveTimeForward(299);
+        mLooper.dispatchAll();
+        verify(mCallback, never()).onClientFinished(any(), anyBoolean());
+
+        mLooper.moveTimeForward(1);
+        mLooper.dispatchAll();
+        verify(mCallback).onClientFinished(any(), eq(true));
+    }
+
     private FingerprintAuthenticationClient createClient() throws RemoteException {
         return createClient(100 /* version */, true /* allowBackgroundAuthentication */);
     }
@@ -520,7 +643,7 @@ public class FingerprintAuthenticationClientTest {
                 null /* taskStackListener */, mLockoutCache,
                 mUdfpsOverlayController, mSideFpsController, allowBackgroundAuthentication,
                 mSensorProps,
-                new Handler(mLooper.getLooper())) {
+                new Handler(mLooper.getLooper()), mClock) {
             @Override
             protected ActivityTaskManager getActivityTaskManager() {
                 return mActivityTaskManager;