diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index 7656407..cbcc85b 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -2742,13 +2742,14 @@
 status_t Camera3Device::registerInFlight(uint32_t frameNumber,
         int32_t numBuffers, CaptureResultExtras resultExtras, bool hasInput,
         bool hasAppCallback, nsecs_t maxExpectedDuration,
-        std::set<String8>& physicalCameraIds, bool isStillCapture) {
+        std::set<String8>& physicalCameraIds, bool isStillCapture,
+        bool isZslCapture) {
     ATRACE_CALL();
     Mutex::Autolock l(mInFlightLock);
 
     ssize_t res;
     res = mInFlightMap.add(frameNumber, InFlightRequest(numBuffers, resultExtras, hasInput,
-            hasAppCallback, maxExpectedDuration, physicalCameraIds, isStillCapture));
+            hasAppCallback, maxExpectedDuration, physicalCameraIds, isStillCapture, isZslCapture));
     if (res < 0) return res;
 
     if (mInFlightMap.size() == 1) {
@@ -2766,11 +2767,12 @@
 
 void Camera3Device::returnOutputBuffers(
         const camera3_stream_buffer_t *outputBuffers, size_t numBuffers,
-        nsecs_t timestamp) {
+        nsecs_t timestamp, bool timestampIncreasing) {
+
     for (size_t i = 0; i < numBuffers; i++)
     {
         Camera3Stream *stream = Camera3Stream::cast(outputBuffers[i].stream);
-        status_t res = stream->returnBuffer(outputBuffers[i], timestamp);
+        status_t res = stream->returnBuffer(outputBuffers[i], timestamp, timestampIncreasing);
         // Note: stream may be deallocated at this point, if this buffer was
         // the last reference to it.
         if (res != OK) {
@@ -3214,8 +3216,9 @@
             request.pendingOutputBuffers.appendArray(result->output_buffers,
                 result->num_output_buffers);
         } else {
+            bool timestampIncreasing = !(request.zslCapture || request.hasInputBuffer);
             returnOutputBuffers(result->output_buffers,
-                result->num_output_buffers, shutterTimestamp);
+                result->num_output_buffers, shutterTimestamp, timestampIncreasing);
         }
 
         if (result->result != NULL && !isPartialResult) {
@@ -3421,8 +3424,9 @@
                     r.collectedPartialResult, msg.frame_number,
                     r.hasInputBuffer, r.physicalMetadatas);
             }
+            bool timestampIncreasing = !(r.zslCapture || r.hasInputBuffer);
             returnOutputBuffers(r.pendingOutputBuffers.array(),
-                r.pendingOutputBuffers.size(), r.shutterTimestamp);
+                r.pendingOutputBuffers.size(), r.shutterTimestamp, timestampIncreasing);
             r.pendingOutputBuffers.clear();
 
             removeInFlightRequestIfReadyLocked(idx);
@@ -4948,6 +4952,7 @@
             hasCallback = false;
         }
         bool isStillCapture = false;
+        bool isZslCapture = false;
         if (!mNextRequests[0].captureRequest->mSettingsList.begin()->metadata.isEmpty()) {
             camera_metadata_ro_entry_t e = camera_metadata_ro_entry_t();
             find_camera_metadata_ro_entry(halRequest->settings, ANDROID_CONTROL_CAPTURE_INTENT, &e);
@@ -4955,13 +4960,18 @@
                 isStillCapture = true;
                 ATRACE_ASYNC_BEGIN("still capture", mNextRequests[i].halRequest.frame_number);
             }
+
+            find_camera_metadata_ro_entry(halRequest->settings, ANDROID_CONTROL_ENABLE_ZSL, &e);
+            if ((e.count > 0) && (e.data.u8[0] == ANDROID_CONTROL_ENABLE_ZSL_TRUE)) {
+                isZslCapture = true;
+            }
         }
         res = parent->registerInFlight(halRequest->frame_number,
                 totalNumBuffers, captureRequest->mResultExtras,
                 /*hasInput*/halRequest->input_buffer != NULL,
                 hasCallback,
                 calculateMaxExpectedDuration(halRequest->settings),
-                requestedPhysicalCameras, isStillCapture);
+                requestedPhysicalCameras, isStillCapture, isZslCapture);
         ALOGVV("%s: registered in flight requestId = %" PRId32 ", frameNumber = %" PRId64
                ", burstId = %" PRId32 ".",
                 __FUNCTION__,
diff --git a/services/camera/libcameraservice/device3/Camera3Device.h b/services/camera/libcameraservice/device3/Camera3Device.h
index 85f9614..159f2ca 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.h
+++ b/services/camera/libcameraservice/device3/Camera3Device.h
@@ -999,6 +999,9 @@
         // Indicates a still capture request.
         bool stillCapture;
 
+        // Indicates a ZSL capture request
+        bool zslCapture;
+
         // Default constructor needed by KeyedVector
         InFlightRequest() :
                 shutterTimestamp(0),
@@ -1010,12 +1013,14 @@
                 hasCallback(true),
                 maxExpectedDuration(kDefaultExpectedDuration),
                 skipResultMetadata(false),
-                stillCapture(false) {
+                stillCapture(false),
+                zslCapture(false) {
         }
 
         InFlightRequest(int numBuffers, CaptureResultExtras extras, bool hasInput,
                 bool hasAppCallback, nsecs_t maxDuration,
-                const std::set<String8>& physicalCameraIdSet, bool isStillCapture) :
+                const std::set<String8>& physicalCameraIdSet, bool isStillCapture, 
+                bool isZslCapture) :
                 shutterTimestamp(0),
                 sensorTimestamp(0),
                 requestStatus(OK),
@@ -1027,7 +1032,8 @@
                 maxExpectedDuration(maxDuration),
                 skipResultMetadata(false),
                 physicalCameraIds(physicalCameraIdSet),
-                stillCapture(isStillCapture) {
+                stillCapture(isStillCapture),
+                zslCapture(isZslCapture) {
         }
     };
 
@@ -1044,7 +1050,7 @@
     status_t registerInFlight(uint32_t frameNumber,
             int32_t numBuffers, CaptureResultExtras resultExtras, bool hasInput,
             bool callback, nsecs_t maxExpectedDuration, std::set<String8>& physicalCameraIds,
-            bool isStillCapture);
+            bool isStillCapture, bool isZslCapture);
 
     /**
      * Returns the maximum expected time it'll take for all currently in-flight
@@ -1154,7 +1160,7 @@
 
     // helper function to return the output buffers to the streams.
     void returnOutputBuffers(const camera3_stream_buffer_t *outputBuffers,
-            size_t numBuffers, nsecs_t timestamp);
+            size_t numBuffers, nsecs_t timestamp, bool timestampIncreasing = true);
 
     // Send a partial capture result.
     void sendPartialCaptureResult(const camera_metadata_t * partialResult,
diff --git a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
index 2c020a2..ec3f35f 100644
--- a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
@@ -268,6 +268,11 @@
             mTraceFirstBuffer = false;
         }
 
+        if (timestamp == 0) {
+            ALOGE("%s: Stream %d: timestamp shouldn't be 0", __FUNCTION__, mId);
+            return BAD_VALUE;
+        }
+
         /* Certain consumers (such as AudioSource or HardwareComposer) use
          * MONOTONIC time, causing time misalignment if camera timestamp is
          * in BOOTTIME. Do the conversion if necessary. */
diff --git a/services/camera/libcameraservice/device3/Camera3Stream.cpp b/services/camera/libcameraservice/device3/Camera3Stream.cpp
index 6030d15..53ff9fe 100644
--- a/services/camera/libcameraservice/device3/Camera3Stream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Stream.cpp
@@ -66,7 +66,8 @@
     mBufferLimitLatency(kBufferLimitLatencyBinSize),
     mFormatOverridden(false),
     mOriginalFormat(-1),
-    mPhysicalCameraId(physicalCameraId) {
+    mPhysicalCameraId(physicalCameraId),
+    mLastTimestamp(0) {
 
     camera3_stream::stream_type = type;
     camera3_stream::width = width;
@@ -649,7 +650,7 @@
 }
 
 status_t Camera3Stream::returnBuffer(const camera3_stream_buffer &buffer,
-        nsecs_t timestamp) {
+        nsecs_t timestamp, bool timestampIncreasing) {
     ATRACE_CALL();
     Mutex::Autolock l(mLock);
 
@@ -661,6 +662,13 @@
 
     removeOutstandingBuffer(buffer);
 
+    if (timestampIncreasing && timestamp != 0 && timestamp <= mLastTimestamp) {
+        ALOGE("%s: Stream %d: timestamp %" PRId64 " is not increasing. Prev timestamp %" PRId64,
+                __FUNCTION__, mId, timestamp, mLastTimestamp);
+        return BAD_VALUE;
+    }
+    mLastTimestamp = timestamp;
+
     /**
      * TODO: Check that the state is valid first.
      *
diff --git a/services/camera/libcameraservice/device3/Camera3Stream.h b/services/camera/libcameraservice/device3/Camera3Stream.h
index 4ddcf1a..e30fc59 100644
--- a/services/camera/libcameraservice/device3/Camera3Stream.h
+++ b/services/camera/libcameraservice/device3/Camera3Stream.h
@@ -320,7 +320,7 @@
      * For bidirectional streams, this method applies to the output-side buffers
      */
     status_t         returnBuffer(const camera3_stream_buffer &buffer,
-            nsecs_t timestamp);
+            nsecs_t timestamp, bool timestampIncreasing);
 
     /**
      * Fill in the camera3_stream_buffer with the next valid buffer for this
@@ -559,6 +559,7 @@
     android_dataspace mOriginalDataSpace;
 
     String8 mPhysicalCameraId;
+    nsecs_t mLastTimestamp;
 }; // class Camera3Stream
 
 }; // namespace camera3
diff --git a/services/camera/libcameraservice/device3/Camera3StreamInterface.h b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
index 9ed7184..bddd2e7 100644
--- a/services/camera/libcameraservice/device3/Camera3StreamInterface.h
+++ b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
@@ -246,7 +246,7 @@
      * For bidirectional streams, this method applies to the output-side buffers
      */
     virtual status_t returnBuffer(const camera3_stream_buffer &buffer,
-            nsecs_t timestamp) = 0;
+            nsecs_t timestamp, bool timestampIncreasing = true) = 0;
 
     /**
      * Fill in the camera3_stream_buffer with the next valid buffer for this