diff --git a/services/sensorservice/CorrectedGyroSensor.cpp b/services/sensorservice/CorrectedGyroSensor.cpp
index b07d544..7b1f346 100644
--- a/services/sensorservice/CorrectedGyroSensor.cpp
+++ b/services/sensorservice/CorrectedGyroSensor.cpp
@@ -58,12 +58,12 @@
 
 status_t CorrectedGyroSensor::activate(void* ident, bool enabled) {
     mSensorDevice.activate(ident, mGyro.getHandle(), enabled);
-    return mSensorFusion.activate(ident, enabled);
+    return mSensorFusion.activate(FUSION_9AXIS, ident, enabled);
 }
 
 status_t CorrectedGyroSensor::setDelay(void* ident, int /*handle*/, int64_t ns) {
     mSensorDevice.setDelay(ident, mGyro.getHandle(), ns);
-    return mSensorFusion.setDelay(ident, ns);
+    return mSensorFusion.setDelay(FUSION_9AXIS, ident, ns);
 }
 
 Sensor CorrectedGyroSensor::getSensor() const {
diff --git a/services/sensorservice/Fusion.cpp b/services/sensorservice/Fusion.cpp
index 4f63c31..359d289 100644
--- a/services/sensorservice/Fusion.cpp
+++ b/services/sensorservice/Fusion.cpp
@@ -24,28 +24,44 @@
 
 // -----------------------------------------------------------------------
 
+/*==================== BEGIN FUSION SENSOR PARAMETER =========================*/
+
+/* Note:
+ *   If a platform uses software fusion, it is necessary to tune the following
+ *   parameters to fit the hardware sensors prior to release.
+ *
+ *   The DEFAULT_ parameters will be used in FUSION_9AXIS and FUSION_NOMAG mode.
+ *   The GEOMAG_ parameters will be used in FUSION_NOGYRO mode.
+ */
+
 /*
- * gyroVAR gives the measured variance of the gyro's output per
+ * GYRO_VAR gives the measured variance of the gyro's output per
  * Hz (or variance at 1 Hz). This is an "intrinsic" parameter of the gyro,
  * which is independent of the sampling frequency.
  *
  * The variance of gyro's output at a given sampling period can be
  * calculated as:
- *      variance(T) = gyroVAR / T
+ *      variance(T) = GYRO_VAR / T
  *
  * The variance of the INTEGRATED OUTPUT at a given sampling period can be
  * calculated as:
- *       variance_integrate_output(T) = gyroVAR * T
- *
+ *       variance_integrate_output(T) = GYRO_VAR * T
  */
-static const float gyroVAR = 1e-7;      // (rad/s)^2 / Hz
-static const float biasVAR = 1e-8;      // (rad/s)^2 / s (guessed)
+static const float DEFAULT_GYRO_VAR = 1e-7;      // (rad/s)^2 / Hz
+static const float DEFAULT_GYRO_BIAS_VAR = 1e-12;  // (rad/s)^2 / s (guessed)
+static const float GEOMAG_GYRO_VAR = 1e-4;      // (rad/s)^2 / Hz
+static const float GEOMAG_GYRO_BIAS_VAR = 1e-8;  // (rad/s)^2 / s (guessed)
 
 /*
  * Standard deviations of accelerometer and magnetometer
  */
-static const float accSTDEV  = 0.05f;   // m/s^2 (measured 0.08 / CDD 0.05)
-static const float magSTDEV  = 0.5f;    // uT    (measured 0.7  / CDD 0.5)
+static const float DEFAULT_ACC_STDEV  = 0.015f; // m/s^2 (measured 0.08 / CDD 0.05)
+static const float DEFAULT_MAG_STDEV  = 0.1f;   // uT    (measured 0.7  / CDD 0.5)
+static const float GEOMAG_ACC_STDEV  = 0.05f; // m/s^2 (measured 0.08 / CDD 0.05)
+static const float GEOMAG_MAG_STDEV  = 0.1f;   // uT    (measured 0.7  / CDD 0.5)
+
+
+/* ====================== END FUSION SENSOR PARAMETER ========================*/
 
 static const float SYMMETRY_TOLERANCE = 1e-10f;
 
@@ -54,7 +70,8 @@
  * ill-conditioning and div by zeros.
  * Threshhold: 10% of g, in m/s^2
  */
-static const float FREE_FALL_THRESHOLD = 0.981f;
+static const float NOMINAL_GRAVITY = 9.81f;
+static const float FREE_FALL_THRESHOLD = 0.1f * (NOMINAL_GRAVITY);
 static const float FREE_FALL_THRESHOLD_SQ =
         FREE_FALL_THRESHOLD*FREE_FALL_THRESHOLD;
 
@@ -87,6 +104,9 @@
 static const float MIN_VALID_CROSS_PRODUCT_MAG_SQ =
     MIN_VALID_CROSS_PRODUCT_MAG*MIN_VALID_CROSS_PRODUCT_MAG;
 
+static const float W_EPS = 1e-4f;
+static const float SQRT_3 = 1.732f;
+static const float WVEC_EPS = 1e-4f/SQRT_3;
 // -----------------------------------------------------------------------
 
 template <typename TYPE, size_t C, size_t R>
@@ -173,7 +193,7 @@
     init();
 }
 
-void Fusion::init() {
+void Fusion::init(int mode) {
     mInitState = 0;
 
     mGyroRate = 0;
@@ -183,6 +203,19 @@
     mCount[2] = 0;
 
     mData = 0;
+    mMode = mode;
+
+    if (mMode != FUSION_NOGYRO) { //normal or game rotation
+        mParam.gyroVar = DEFAULT_GYRO_VAR;
+        mParam.gyroBiasVar = DEFAULT_GYRO_BIAS_VAR;
+        mParam.accStdev = DEFAULT_ACC_STDEV;
+        mParam.magStdev = DEFAULT_MAG_STDEV;
+    } else {
+        mParam.gyroVar = GEOMAG_GYRO_VAR;
+        mParam.gyroBiasVar = GEOMAG_GYRO_BIAS_VAR;
+        mParam.accStdev = GEOMAG_ACC_STDEV;
+        mParam.magStdev = GEOMAG_MAG_STDEV;
+    }
 }
 
 void Fusion::initFusion(const vec4_t& q, float dT)
@@ -205,11 +238,11 @@
     const float dT3 = dT2*dT;
 
     // variance of integrated output at 1/dT Hz (random drift)
-    const float q00 = gyroVAR * dT + 0.33333f * biasVAR * dT3;
+    const float q00 = mParam.gyroVar * dT + 0.33333f * mParam.gyroBiasVar * dT3;
 
     // variance of drift rate ramp
-    const float q11 = biasVAR * dT;
-    const float q10 = 0.5f * biasVAR * dT2;
+    const float q11 = mParam.gyroBiasVar * dT;
+    const float q10 = 0.5f * mParam.gyroBiasVar * dT2;
     const float q01 = q10;
 
     GQGt[0][0] =  q00;      // rad^2
@@ -223,7 +256,9 @@
 }
 
 bool Fusion::hasEstimate() const {
-    return (mInitState == (MAG|ACC|GYRO));
+    return ((mInitState & MAG) || (mMode == FUSION_NOMAG)) &&
+           ((mInitState & GYRO) || (mMode == FUSION_NOGYRO)) &&
+           (mInitState & ACC);
 }
 
 bool Fusion::checkInitComplete(int what, const vec3_t& d, float dT) {
@@ -234,6 +269,9 @@
         mData[0] += d * (1/length(d));
         mCount[0]++;
         mInitState |= ACC;
+        if (mMode == FUSION_NOGYRO ) {
+            mGyroRate = dT;
+        }
     } else if (what == MAG) {
         mData[1] += d * (1/length(d));
         mCount[1]++;
@@ -242,25 +280,29 @@
         mGyroRate = dT;
         mData[2] += d*dT;
         mCount[2]++;
-        if (mCount[2] == 64) {
-            // 64 samples is good enough to estimate the gyro drift and
-            // doesn't take too much time.
-            mInitState |= GYRO;
-        }
+        mInitState |= GYRO;
     }
 
-    if (mInitState == (MAG|ACC|GYRO)) {
+    if (hasEstimate()) {
         // Average all the values we collected so far
         mData[0] *= 1.0f/mCount[0];
-        mData[1] *= 1.0f/mCount[1];
+        if (mMode != FUSION_NOMAG) {
+            mData[1] *= 1.0f/mCount[1];
+        }
         mData[2] *= 1.0f/mCount[2];
 
         // calculate the MRPs from the data collection, this gives us
         // a rough estimate of our initial state
         mat33_t R;
-        vec3_t up(mData[0]);
-        vec3_t east(cross_product(mData[1], up));
-        east *= 1/length(east);
+        vec3_t  up(mData[0]);
+        vec3_t  east;
+
+        if (mMode != FUSION_NOMAG) {
+            east = normalize(cross_product(mData[1], up));
+        } else {
+            east = getOrthogonal(up);
+        }
+
         vec3_t north(cross_product(up, east));
         R << east << north << up;
         const vec4_t q = matrixToQuat(R);
@@ -278,21 +320,43 @@
     predict(w, dT);
 }
 
-status_t Fusion::handleAcc(const vec3_t& a) {
+status_t Fusion::handleAcc(const vec3_t& a, float dT) {
+    if (!checkInitComplete(ACC, a, dT))
+        return BAD_VALUE;
+
     // ignore acceleration data if we're close to free-fall
-    if (length_squared(a) < FREE_FALL_THRESHOLD_SQ) {
+    const float l = length(a);
+    if (l < FREE_FALL_THRESHOLD) {
         return BAD_VALUE;
     }
 
-    if (!checkInitComplete(ACC, a))
-        return BAD_VALUE;
+    const float l_inv = 1.0f/l;
 
-    const float l = 1/length(a);
-    update(a*l, Ba, accSTDEV*l);
+    if ( mMode == FUSION_NOGYRO ) {
+        //geo mag
+        vec3_t w_dummy;
+        w_dummy = x1; //bias
+        predict(w_dummy, dT);
+    }
+
+    if ( mMode == FUSION_NOMAG) {
+        vec3_t m;
+        m = getRotationMatrix()*Bm;
+        update(m, Bm, mParam.magStdev);
+    }
+
+    vec3_t unityA = a * l_inv;
+    const float d = sqrtf(fabsf(l- NOMINAL_GRAVITY));
+    const float p = l_inv * mParam.accStdev*expf(d);
+
+    update(unityA, Ba, p);
     return NO_ERROR;
 }
 
 status_t Fusion::handleMag(const vec3_t& m) {
+    if (!checkInitComplete(MAG, m))
+        return BAD_VALUE;
+
     // the geomagnetic-field should be between 30uT and 60uT
     // reject if too large to avoid spurious magnetic sources
     const float magFieldSq = length_squared(m);
@@ -304,9 +368,6 @@
         return BAD_VALUE;
     }
 
-    if (!checkInitComplete(MAG, m))
-        return BAD_VALUE;
-
     // Orthogonalize the magnetic field to the gravity field, mapping it into
     // tangent to Earth.
     const vec3_t up( getRotationMatrix() * Ba );
@@ -324,10 +385,10 @@
     // then pass it in as the update.
     vec3_t north( cross_product(up, east) );
 
-    const float l = 1 / length(north);
-    north *= l;
+    const float l_inv = 1 / length(north);
+    north *= l_inv;
 
-    update(north, Bm, magSTDEV*l);
+    update(north, Bm,  mParam.magStdev*l_inv);
     return NO_ERROR;
 }
 
@@ -372,8 +433,11 @@
 void Fusion::predict(const vec3_t& w, float dT) {
     const vec4_t q  = x0;
     const vec3_t b  = x1;
-    const vec3_t we = w - b;
+    vec3_t we = w - b;
 
+    if (length(we) < WVEC_EPS) {
+        we = (we[0]>0.f)?WVEC_EPS:-WVEC_EPS;
+    }
     // q(k+1) = O(we)*q(k)
     // --------------------
     //
@@ -406,7 +470,7 @@
     const mat33_t wx2(wx*wx);
     const float lwedT = length(we)*dT;
     const float hlwedT = 0.5f*lwedT;
-    const float ilwe = 1/length(we);
+    const float ilwe = 1.f/length(we);
     const float k0 = (1-cosf(lwedT))*(ilwe*ilwe);
     const float k1 = sinf(lwedT);
     const float k2 = cosf(hlwedT);
@@ -422,6 +486,7 @@
     Phi[1][0] = wx*k0 - I33dT - wx2*(ilwe*ilwe*ilwe)*(lwedT-k1);
 
     x0 = O*q;
+
     if (x0.w < 0)
         x0 = -x0;
 
@@ -466,15 +531,37 @@
 
     const vec3_t e(z - Bb);
     const vec3_t dq(K[0]*e);
-    const vec3_t db(K[1]*e);
 
     q += getF(q)*(0.5f*dq);
     x0 = normalize_quat(q);
-    x1 += db;
+
+    if (mMode != FUSION_NOMAG) {
+        const vec3_t db(K[1]*e);
+        x1 += db;
+    }
 
     checkState();
 }
 
+vec3_t Fusion::getOrthogonal(const vec3_t &v) {
+    vec3_t w;
+    if (fabsf(v[0])<= fabsf(v[1]) && fabsf(v[0]) <= fabsf(v[2]))  {
+        w[0]=0.f;
+        w[1] = v[2];
+        w[2] = -v[1];
+    } else if (fabsf(v[1]) <= fabsf(v[2])) {
+        w[0] = v[2];
+        w[1] = 0.f;
+        w[2] = -v[0];
+    }else {
+        w[0] = v[1];
+        w[1] = -v[0];
+        w[2] = 0.f;
+    }
+    return normalize(w);
+}
+
+
 // -----------------------------------------------------------------------
 
 }; // namespace android
diff --git a/services/sensorservice/Fusion.h b/services/sensorservice/Fusion.h
index 7062999..602779f 100644
--- a/services/sensorservice/Fusion.h
+++ b/services/sensorservice/Fusion.h
@@ -27,6 +27,13 @@
 
 typedef mat<float, 3, 4> mat34_t;
 
+enum FUSION_MODE{
+    FUSION_9AXIS, // use accel gyro mag
+    FUSION_NOMAG, // use accel gyro (game rotation, gravity)
+    FUSION_NOGYRO, // use accel mag (geomag rotation)
+    NUM_FUSION_MODE
+};
+
 class Fusion {
     /*
      * the state vector is made of two sub-vector containing respectively:
@@ -55,9 +62,9 @@
 
 public:
     Fusion();
-    void init();
+    void init(int mode = FUSION_9AXIS);
     void handleGyro(const vec3_t& w, float dT);
-    status_t handleAcc(const vec3_t& a);
+    status_t handleAcc(const vec3_t& a, float dT);
     status_t handleMag(const vec3_t& m);
     vec4_t getAttitude() const;
     vec3_t getBias() const;
@@ -65,12 +72,21 @@
     bool hasEstimate() const;
 
 private:
+    struct Parameter {
+        float gyroVar;
+        float gyroBiasVar;
+        float accStdev;
+        float magStdev;
+    } mParam;
+
     mat<mat33_t, 2, 2> Phi;
     vec3_t Ba, Bm;
     uint32_t mInitState;
     float mGyroRate;
     vec<vec3_t, 3> mData;
     size_t mCount[3];
+    int mMode;
+
     enum { ACC=0x1, MAG=0x2, GYRO=0x4 };
     bool checkInitComplete(int, const vec3_t& w, float d = 0);
     void initFusion(const vec4_t& q0, float dT);
@@ -78,6 +94,7 @@
     void predict(const vec3_t& w, float dT);
     void update(const vec3_t& z, const vec3_t& Bi, float sigma);
     static mat34_t getF(const vec4_t& p);
+    static vec3_t getOrthogonal(const vec3_t &v);
 };
 
 }; // namespace android
diff --git a/services/sensorservice/GravitySensor.cpp b/services/sensorservice/GravitySensor.cpp
index 61118bc..a165a5b 100644
--- a/services/sensorservice/GravitySensor.cpp
+++ b/services/sensorservice/GravitySensor.cpp
@@ -46,9 +46,9 @@
 {
     if (event.type == SENSOR_TYPE_ACCELEROMETER) {
         vec3_t g;
-        if (!mSensorFusion.hasEstimate())
+        if (!mSensorFusion.hasEstimate(FUSION_NOMAG))
             return false;
-        const mat33_t R(mSensorFusion.getRotationMatrix());
+        const mat33_t R(mSensorFusion.getRotationMatrix(FUSION_NOMAG));
         // FIXME: we need to estimate the length of gravity because
         // the accelerometer may have a small scaling error. This
         // translates to an offset in the linear-acceleration sensor.
@@ -66,11 +66,11 @@
 }
 
 status_t GravitySensor::activate(void* ident, bool enabled) {
-    return mSensorFusion.activate(ident, enabled);
+    return mSensorFusion.activate(FUSION_NOMAG, ident, enabled);
 }
 
 status_t GravitySensor::setDelay(void* ident, int /*handle*/, int64_t ns) {
-    return mSensorFusion.setDelay(ident, ns);
+    return mSensorFusion.setDelay(FUSION_NOMAG, ident, ns);
 }
 
 Sensor GravitySensor::getSensor() const {
diff --git a/services/sensorservice/OrientationSensor.cpp b/services/sensorservice/OrientationSensor.cpp
index 6d85cca..d55f336 100644
--- a/services/sensorservice/OrientationSensor.cpp
+++ b/services/sensorservice/OrientationSensor.cpp
@@ -66,11 +66,11 @@
 }
 
 status_t OrientationSensor::activate(void* ident, bool enabled) {
-    return mSensorFusion.activate(ident, enabled);
+    return mSensorFusion.activate(FUSION_9AXIS, ident, enabled);
 }
 
 status_t OrientationSensor::setDelay(void* ident, int /*handle*/, int64_t ns) {
-    return mSensorFusion.setDelay(ident, ns);
+    return mSensorFusion.setDelay(FUSION_9AXIS, ident, ns);
 }
 
 Sensor OrientationSensor::getSensor() const {
diff --git a/services/sensorservice/RotationVectorSensor.cpp b/services/sensorservice/RotationVectorSensor.cpp
index cb305eb..238845b 100644
--- a/services/sensorservice/RotationVectorSensor.cpp
+++ b/services/sensorservice/RotationVectorSensor.cpp
@@ -27,9 +27,10 @@
 namespace android {
 // ---------------------------------------------------------------------------
 
-RotationVectorSensor::RotationVectorSensor()
+RotationVectorSensor::RotationVectorSensor(int mode)
     : mSensorDevice(SensorDevice::getInstance()),
-      mSensorFusion(SensorFusion::getInstance())
+      mSensorFusion(SensorFusion::getInstance()),
+      mMode(mode)
 {
 }
 
@@ -37,15 +38,15 @@
         const sensors_event_t& event)
 {
     if (event.type == SENSOR_TYPE_ACCELEROMETER) {
-        if (mSensorFusion.hasEstimate()) {
-            const vec4_t q(mSensorFusion.getAttitude());
+        if (mSensorFusion.hasEstimate(mMode)) {
+            const vec4_t q(mSensorFusion.getAttitude(mMode));
             *outEvent = event;
             outEvent->data[0] = q.x;
             outEvent->data[1] = q.y;
             outEvent->data[2] = q.z;
             outEvent->data[3] = q.w;
-            outEvent->sensor = '_rov';
-            outEvent->type = SENSOR_TYPE_ROTATION_VECTOR;
+            outEvent->sensor = getSensorToken();
+            outEvent->type = getSensorType();
             return true;
         }
     }
@@ -53,20 +54,20 @@
 }
 
 status_t RotationVectorSensor::activate(void* ident, bool enabled) {
-    return mSensorFusion.activate(ident, enabled);
+    return mSensorFusion.activate(mMode, ident, enabled);
 }
 
 status_t RotationVectorSensor::setDelay(void* ident, int /*handle*/, int64_t ns) {
-    return mSensorFusion.setDelay(ident, ns);
+    return mSensorFusion.setDelay(mMode, ident, ns);
 }
 
 Sensor RotationVectorSensor::getSensor() const {
     sensor_t hwSensor;
-    hwSensor.name       = "Rotation Vector Sensor";
+    hwSensor.name       = getSensorName();
     hwSensor.vendor     = "AOSP";
     hwSensor.version    = 3;
-    hwSensor.handle     = '_rov';
-    hwSensor.type       = SENSOR_TYPE_ROTATION_VECTOR;
+    hwSensor.handle     = getSensorToken();
+    hwSensor.type       = getSensorType();
     hwSensor.maxRange   = 1;
     hwSensor.resolution = 1.0f / (1<<24);
     hwSensor.power      = mSensorFusion.getPowerUsage();
@@ -75,6 +76,48 @@
     return sensor;
 }
 
+int RotationVectorSensor::getSensorType() const {
+    switch(mMode) {
+        case FUSION_9AXIS:
+            return SENSOR_TYPE_ROTATION_VECTOR;
+        case FUSION_NOMAG:
+            return SENSOR_TYPE_GAME_ROTATION_VECTOR;
+        case FUSION_NOGYRO:
+            return SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR;
+        default:
+            assert(0);
+            return 0;
+    }
+}
+
+const char* RotationVectorSensor::getSensorName() const {
+    switch(mMode) {
+        case FUSION_9AXIS:
+            return "Rotation Vector Sensor";
+        case FUSION_NOMAG:
+            return "Game Rotation Vector Sensor";
+        case FUSION_NOGYRO:
+            return "GeoMag Rotation Vector Sensor";
+        default:
+            assert(0);
+            return NULL;
+    }
+}
+
+int RotationVectorSensor::getSensorToken() const {
+    switch(mMode) {
+        case FUSION_9AXIS:
+            return '_rov';
+        case FUSION_NOMAG:
+            return '_gar';
+        case FUSION_NOGYRO:
+            return '_geo';
+        default:
+            assert(0);
+            return 0;
+    }
+}
+
 // ---------------------------------------------------------------------------
 
 GyroDriftSensor::GyroDriftSensor()
@@ -102,11 +145,11 @@
 }
 
 status_t GyroDriftSensor::activate(void* ident, bool enabled) {
-    return mSensorFusion.activate(ident, enabled);
+    return mSensorFusion.activate(FUSION_9AXIS, ident, enabled);
 }
 
 status_t GyroDriftSensor::setDelay(void* ident, int /*handle*/, int64_t ns) {
-    return mSensorFusion.setDelay(ident, ns);
+    return mSensorFusion.setDelay(FUSION_9AXIS, ident, ns);
 }
 
 Sensor GyroDriftSensor::getSensor() const {
diff --git a/services/sensorservice/RotationVectorSensor.h b/services/sensorservice/RotationVectorSensor.h
index bb97fe1..1fc316b 100644
--- a/services/sensorservice/RotationVectorSensor.h
+++ b/services/sensorservice/RotationVectorSensor.h
@@ -35,9 +35,14 @@
 class RotationVectorSensor : public SensorInterface {
     SensorDevice& mSensorDevice;
     SensorFusion& mSensorFusion;
+    int mMode;
+
+    int getSensorType() const;
+    const char* getSensorName() const ;
+    int getSensorToken() const ;
 
 public:
-    RotationVectorSensor();
+    RotationVectorSensor(int mode = FUSION_9AXIS);
     virtual bool process(sensors_event_t* outEvent,
             const sensors_event_t& event);
     virtual status_t activate(void* ident, bool enabled);
@@ -46,6 +51,16 @@
     virtual bool isVirtual() const { return true; }
 };
 
+class GameRotationVectorSensor : public RotationVectorSensor {
+public:
+    GameRotationVectorSensor() : RotationVectorSensor(FUSION_NOMAG) {}
+};
+
+class GeoMagRotationVectorSensor : public RotationVectorSensor {
+public:
+    GeoMagRotationVectorSensor() : RotationVectorSensor(FUSION_NOGYRO) {}
+};
+
 class GyroDriftSensor : public SensorInterface {
     SensorDevice& mSensorDevice;
     SensorFusion& mSensorFusion;
diff --git a/services/sensorservice/SensorFusion.cpp b/services/sensorservice/SensorFusion.cpp
index 6d93009..9863f62 100644
--- a/services/sensorservice/SensorFusion.cpp
+++ b/services/sensorservice/SensorFusion.cpp
@@ -25,11 +25,17 @@
 
 SensorFusion::SensorFusion()
     : mSensorDevice(SensorDevice::getInstance()),
-      mEnabled(false), mGyroTime(0)
+      mAttitude(mAttitudes[FUSION_9AXIS]),
+      mGyroTime(0), mAccTime(0)
 {
     sensor_t const* list;
     Sensor uncalibratedGyro;
     ssize_t count = mSensorDevice.getSensorList(&list);
+
+    mEnabled[FUSION_9AXIS] = false;
+    mEnabled[FUSION_NOMAG] = false;
+    mEnabled[FUSION_NOGYRO] = false;
+
     if (count > 0) {
         for (size_t i=0 ; i<size_t(count) ; i++) {
             if (list[i].type == SENSOR_TYPE_ACCELEROMETER) {
@@ -55,81 +61,121 @@
         // and power/cpu usage.
         mEstimatedGyroRate = 200;
         mTargetDelayNs = 1000000000LL/mEstimatedGyroRate;
-        mFusion.init();
+
+        for (int i = 0; i<NUM_FUSION_MODE; ++i) {
+            mFusions[i].init(i);
+        }
     }
 }
 
 void SensorFusion::process(const sensors_event_t& event) {
+
     if (event.type == mGyro.getType()) {
-        if (mGyroTime != 0) {
-            const float dT = (event.timestamp - mGyroTime) / 1000000000.0f;
-            mFusion.handleGyro(vec3_t(event.data), dT);
+        float dT;
+        if ( event.timestamp - mGyroTime> 0 &&
+             event.timestamp - mGyroTime< (int64_t)(5e7) ) { //0.05sec
+
+            dT = (event.timestamp - mGyroTime) / 1000000000.0f;
             // here we estimate the gyro rate (useful for debugging)
             const float freq = 1 / dT;
             if (freq >= 100 && freq<1000) { // filter values obviously wrong
                 const float alpha = 1 / (1 + dT); // 1s time-constant
                 mEstimatedGyroRate = freq + (mEstimatedGyroRate - freq)*alpha;
             }
+
+            const vec3_t gyro(event.data);
+            for (int i = 0; i<NUM_FUSION_MODE; ++i) {
+                if (mEnabled[i]) {
+                    // fusion in no gyro mode will ignore
+                    mFusions[i].handleGyro(gyro, dT);
+                }
+            }
         }
         mGyroTime = event.timestamp;
     } else if (event.type == SENSOR_TYPE_MAGNETIC_FIELD) {
         const vec3_t mag(event.data);
-        mFusion.handleMag(mag);
+        for (int i = 0; i<NUM_FUSION_MODE; ++i) {
+            if (mEnabled[i]) {
+                mFusions[i].handleMag(mag);// fusion in no mag mode will ignore
+            }
+        }
     } else if (event.type == SENSOR_TYPE_ACCELEROMETER) {
-        const vec3_t acc(event.data);
-        mFusion.handleAcc(acc);
-        mAttitude = mFusion.getAttitude();
+        float dT;
+        if ( event.timestamp - mAccTime> 0 &&
+             event.timestamp - mAccTime< (int64_t)(1e8) ) { //0.1sec
+            dT = (event.timestamp - mAccTime) / 1000000000.0f;
+
+            const vec3_t acc(event.data);
+            for (int i = 0; i<NUM_FUSION_MODE; ++i) {
+                if (mEnabled[i]) {
+                    mFusions[i].handleAcc(acc, dT);
+                    mAttitudes[i] = mFusions[i].getAttitude();
+                }
+            }
+        }
+        mAccTime = event.timestamp;
     }
 }
 
 template <typename T> inline T min(T a, T b) { return a<b ? a : b; }
 template <typename T> inline T max(T a, T b) { return a>b ? a : b; }
 
-status_t SensorFusion::activate(void* ident, bool enabled) {
+status_t SensorFusion::activate(int mode, void* ident, bool enabled) {
 
     ALOGD_IF(DEBUG_CONNECTIONS,
-            "SensorFusion::activate(ident=%p, enabled=%d)",
-            ident, enabled);
+            "SensorFusion::activate(mode=%d, ident=%p, enabled=%d)",
+            mode, ident, enabled);
 
-    const ssize_t idx = mClients.indexOf(ident);
+    const ssize_t idx = mClients[mode].indexOf(ident);
     if (enabled) {
         if (idx < 0) {
-            mClients.add(ident);
+            mClients[mode].add(ident);
         }
     } else {
         if (idx >= 0) {
-            mClients.removeItemsAt(idx);
+            mClients[mode].removeItemsAt(idx);
+        }
+    }
+
+    const bool newState = mClients[mode].size() != 0;
+    if (newState != mEnabled[mode]) {
+        mEnabled[mode] = newState;
+        if (newState) {
+            mFusions[mode].init(mode);
         }
     }
 
     mSensorDevice.activate(ident, mAcc.getHandle(), enabled);
-    mSensorDevice.activate(ident, mMag.getHandle(), enabled);
-    mSensorDevice.activate(ident, mGyro.getHandle(), enabled);
+    if (mode != FUSION_NOMAG) {
+        mSensorDevice.activate(ident, mMag.getHandle(), enabled);
+    }
+    if (mode != FUSION_NOGYRO) {
+        mSensorDevice.activate(ident, mGyro.getHandle(), enabled);
+    }
 
-    const bool newState = mClients.size() != 0;
-    if (newState != mEnabled) {
-        mEnabled = newState;
-        if (newState) {
-            mFusion.init();
-            mGyroTime = 0;
-        }
+    return NO_ERROR;
+}
+
+status_t SensorFusion::setDelay(int mode, void* ident, int64_t ns) {
+    // Call batch with timeout zero instead of setDelay().
+    if (ns > (int64_t)5e7) {
+        ns = (int64_t)(5e7);
+    }
+    mSensorDevice.batch(ident, mAcc.getHandle(), 0, ns, 0);
+    if (mode != FUSION_NOMAG) {
+        mSensorDevice.batch(ident, mMag.getHandle(), 0, ms2ns(20), 0);
+    }
+    if (mode != FUSION_NOGYRO) {
+        mSensorDevice.batch(ident, mGyro.getHandle(), 0, mTargetDelayNs, 0);
     }
     return NO_ERROR;
 }
 
-status_t SensorFusion::setDelay(void* ident, int64_t ns) {
-    // Call batch with timeout zero instead of setDelay().
-    mSensorDevice.batch(ident, mAcc.getHandle(), 0, ns, 0);
-    mSensorDevice.batch(ident, mMag.getHandle(), 0, ms2ns(20), 0);
-    mSensorDevice.batch(ident, mGyro.getHandle(), 0, mTargetDelayNs, 0);
-    return NO_ERROR;
-}
 
-
-float SensorFusion::getPowerUsage() const {
+float SensorFusion::getPowerUsage(int mode) const {
     float power =   mAcc.getPowerUsage() +
-                    mMag.getPowerUsage() +
-                    mGyro.getPowerUsage();
+                    ((mode != FUSION_NOMAG) ? mMag.getPowerUsage() : 0) +
+                    ((mode != FUSION_NOGYRO) ? mGyro.getPowerUsage() : 0);
     return power;
 }
 
@@ -138,21 +184,55 @@
 }
 
 void SensorFusion::dump(String8& result) {
-    const Fusion& fusion(mFusion);
+    const Fusion& fusion_9axis(mFusions[FUSION_9AXIS]);
     result.appendFormat("9-axis fusion %s (%zd clients), gyro-rate=%7.2fHz, "
             "q=< %g, %g, %g, %g > (%g), "
             "b=< %g, %g, %g >\n",
-            mEnabled ? "enabled" : "disabled",
-            mClients.size(),
+            mEnabled[FUSION_9AXIS] ? "enabled" : "disabled",
+            mClients[FUSION_9AXIS].size(),
             mEstimatedGyroRate,
-            fusion.getAttitude().x,
-            fusion.getAttitude().y,
-            fusion.getAttitude().z,
-            fusion.getAttitude().w,
-            length(fusion.getAttitude()),
-            fusion.getBias().x,
-            fusion.getBias().y,
-            fusion.getBias().z);
+            fusion_9axis.getAttitude().x,
+            fusion_9axis.getAttitude().y,
+            fusion_9axis.getAttitude().z,
+            fusion_9axis.getAttitude().w,
+            length(fusion_9axis.getAttitude()),
+            fusion_9axis.getBias().x,
+            fusion_9axis.getBias().y,
+            fusion_9axis.getBias().z);
+
+    const Fusion& fusion_nomag(mFusions[FUSION_NOMAG]);
+    result.appendFormat("game fusion(no mag) %s (%zd clients), "
+            "gyro-rate=%7.2fHz, "
+            "q=< %g, %g, %g, %g > (%g), "
+            "b=< %g, %g, %g >\n",
+            mEnabled[FUSION_NOMAG] ? "enabled" : "disabled",
+            mClients[FUSION_NOMAG].size(),
+            mEstimatedGyroRate,
+            fusion_nomag.getAttitude().x,
+            fusion_nomag.getAttitude().y,
+            fusion_nomag.getAttitude().z,
+            fusion_nomag.getAttitude().w,
+            length(fusion_nomag.getAttitude()),
+            fusion_nomag.getBias().x,
+            fusion_nomag.getBias().y,
+            fusion_nomag.getBias().z);
+
+    const Fusion& fusion_nogyro(mFusions[FUSION_NOGYRO]);
+    result.appendFormat("geomag fusion (no gyro) %s (%zd clients), "
+            "gyro-rate=%7.2fHz, "
+            "q=< %g, %g, %g, %g > (%g), "
+            "b=< %g, %g, %g >\n",
+            mEnabled[FUSION_NOGYRO] ? "enabled" : "disabled",
+            mClients[FUSION_NOGYRO].size(),
+            mEstimatedGyroRate,
+            fusion_nogyro.getAttitude().x,
+            fusion_nogyro.getAttitude().y,
+            fusion_nogyro.getAttitude().z,
+            fusion_nogyro.getAttitude().w,
+            length(fusion_nogyro.getAttitude()),
+            fusion_nogyro.getBias().x,
+            fusion_nogyro.getBias().y,
+            fusion_nogyro.getBias().z);
 }
 
 // ---------------------------------------------------------------------------
diff --git a/services/sensorservice/SensorFusion.h b/services/sensorservice/SensorFusion.h
index 432adbc..ad636d5 100644
--- a/services/sensorservice/SensorFusion.h
+++ b/services/sensorservice/SensorFusion.h
@@ -42,30 +42,52 @@
     Sensor mAcc;
     Sensor mMag;
     Sensor mGyro;
-    Fusion mFusion;
-    bool mEnabled;
+
+    Fusion mFusions[NUM_FUSION_MODE]; // normal, no_mag, no_gyro
+
+    bool mEnabled[NUM_FUSION_MODE];
+
+    vec4_t &mAttitude;
+    vec4_t mAttitudes[NUM_FUSION_MODE];
+
+    SortedVector<void*> mClients[3];
+
     float mEstimatedGyroRate;
     nsecs_t mTargetDelayNs;
+
     nsecs_t mGyroTime;
-    vec4_t mAttitude;
-    SortedVector<void*> mClients;
+    nsecs_t mAccTime;
 
     SensorFusion();
 
 public:
     void process(const sensors_event_t& event);
 
-    bool isEnabled() const { return mEnabled; }
-    bool hasEstimate() const { return mFusion.hasEstimate(); }
-    mat33_t getRotationMatrix() const { return mFusion.getRotationMatrix(); }
-    vec4_t getAttitude() const { return mAttitude; }
-    vec3_t getGyroBias() const { return mFusion.getBias(); }
+    bool isEnabled() const {
+        return mEnabled[FUSION_9AXIS] ||
+                mEnabled[FUSION_NOMAG] ||
+                mEnabled[FUSION_NOGYRO];
+    }
+
+    bool hasEstimate(int mode = FUSION_9AXIS) const {
+        return mFusions[mode].hasEstimate();
+    }
+
+    mat33_t getRotationMatrix(int mode = FUSION_9AXIS) const {
+        return mFusions[mode].getRotationMatrix();
+    }
+
+    vec4_t getAttitude(int mode = FUSION_9AXIS) const {
+        return mAttitudes[mode];
+    }
+
+    vec3_t getGyroBias() const { return mFusions[FUSION_9AXIS].getBias(); }
     float getEstimatedRate() const { return mEstimatedGyroRate; }
 
-    status_t activate(void* ident, bool enabled);
-    status_t setDelay(void* ident, int64_t ns);
+    status_t activate(int mode, void* ident, bool enabled);
+    status_t setDelay(int mode, void* ident, int64_t ns);
 
-    float getPowerUsage() const;
+    float getPowerUsage(int mode=FUSION_9AXIS) const;
     int32_t getMinDelay() const;
 
     void dump(String8& result);
diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index 1a486a3..8e2109b 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -88,11 +88,14 @@
             uint32_t virtualSensorsNeeds =
                     (1<<SENSOR_TYPE_GRAVITY) |
                     (1<<SENSOR_TYPE_LINEAR_ACCELERATION) |
-                    (1<<SENSOR_TYPE_ROTATION_VECTOR);
+                    (1<<SENSOR_TYPE_ROTATION_VECTOR) |
+                    (1<<SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR) |
+                    (1<<SENSOR_TYPE_GAME_ROTATION_VECTOR);
 
             mLastEventSeen.setCapacity(count);
             for (ssize_t i=0 ; i<count ; i++) {
-                registerSensor( new HardwareSensor(list[i]) );
+                bool useThisSensor=true;
+
                 switch (list[i].type) {
                     case SENSOR_TYPE_ACCELEROMETER:
                         hasAccel = true;
@@ -110,9 +113,18 @@
                     case SENSOR_TYPE_GRAVITY:
                     case SENSOR_TYPE_LINEAR_ACCELERATION:
                     case SENSOR_TYPE_ROTATION_VECTOR:
-                        virtualSensorsNeeds &= ~(1<<list[i].type);
+                    case SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR:
+                    case SENSOR_TYPE_GAME_ROTATION_VECTOR:
+                        if (IGNORE_HARDWARE_FUSION) {
+                            useThisSensor = false;
+                        } else {
+                            virtualSensorsNeeds &= ~(1<<list[i].type);
+                        }
                         break;
                 }
+                if (useThisSensor) {
+                    registerSensor( new HardwareSensor(list[i]) );
+                }
             }
 
             // it's safe to instantiate the SensorFusion object here
@@ -124,26 +136,15 @@
             mUserSensorList = mSensorList;
 
             if (hasGyro && hasAccel && hasMag) {
-                Sensor aSensor;
-
                 // Add Android virtual sensors if they're not already
                 // available in the HAL
+                Sensor aSensor;
 
                 aSensor = registerVirtualSensor( new RotationVectorSensor() );
                 if (virtualSensorsNeeds & (1<<SENSOR_TYPE_ROTATION_VECTOR)) {
                     mUserSensorList.add(aSensor);
                 }
 
-                aSensor = registerVirtualSensor( new GravitySensor(list, count) );
-                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_GRAVITY)) {
-                    mUserSensorList.add(aSensor);
-                }
-
-                aSensor = registerVirtualSensor( new LinearAccelerationSensor(list, count) );
-                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_LINEAR_ACCELERATION)) {
-                    mUserSensorList.add(aSensor);
-                }
-
                 aSensor = registerVirtualSensor( new OrientationSensor() );
                 if (virtualSensorsNeeds & (1<<SENSOR_TYPE_ROTATION_VECTOR)) {
                     // if we are doing our own rotation-vector, also add
@@ -151,11 +152,46 @@
                     mUserSensorList.replaceAt(aSensor, orientationIndex);
                 }
 
+                aSensor = registerVirtualSensor(
+                                new LinearAccelerationSensor(list, count) );
+                if (virtualSensorsNeeds &
+                            (1<<SENSOR_TYPE_LINEAR_ACCELERATION)) {
+                    mUserSensorList.add(aSensor);
+                }
+
                 // virtual debugging sensors are not added to mUserSensorList
                 registerVirtualSensor( new CorrectedGyroSensor(list, count) );
                 registerVirtualSensor( new GyroDriftSensor() );
             }
 
+            if (hasAccel && hasGyro) {
+                Sensor aSensor;
+
+                aSensor = registerVirtualSensor(
+                                new GravitySensor(list, count) );
+                if (virtualSensorsNeeds & (1<<SENSOR_TYPE_GRAVITY)) {
+                    mUserSensorList.add(aSensor);
+                }
+
+                aSensor = registerVirtualSensor(
+                                new GameRotationVectorSensor() );
+                if (virtualSensorsNeeds &
+                            (1<<SENSOR_TYPE_GAME_ROTATION_VECTOR)) {
+                    mUserSensorList.add(aSensor);
+                }
+            }
+
+            if (hasAccel && hasMag) {
+                Sensor aSensor;
+
+                aSensor = registerVirtualSensor(
+                                new GeoMagRotationVectorSensor() );
+                if (virtualSensorsNeeds &
+                        (1<<SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR)) {
+                    mUserSensorList.add(aSensor);
+                }
+            }
+
             // debugging sensor list
             mUserSensorListDebug = mSensorList;
 
diff --git a/services/sensorservice/SensorService.h b/services/sensorservice/SensorService.h
index 9a573ae..7d81d6e 100644
--- a/services/sensorservice/SensorService.h
+++ b/services/sensorservice/SensorService.h
@@ -46,7 +46,7 @@
 #endif
 
 // ---------------------------------------------------------------------------
-
+#define IGNORE_HARDWARE_FUSION  false
 #define DEBUG_CONNECTIONS   false
 // Max size is 100 KB which is enough to accept a batch of about 1000 events.
 #define MAX_SOCKET_BUFFER_SIZE_BATCHED 100 * 1024