diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index 7bf3e0a..f4be168 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -40,6 +40,7 @@
 
 #include "GLExtensions.h"
 #include "HWComposer.h"
+#include "SurfaceFlinger.h"
 
 using namespace android;
 
@@ -75,7 +76,7 @@
         const sp<SurfaceFlinger>& flinger,
         uint32_t dpy)
     : DisplayHardwareBase(flinger, dpy),
-      mFlags(0), mHwc(0)
+      mFlinger(flinger), mFlags(0), mHwc(0)
 {
     init(dpy);
 }
@@ -310,7 +311,7 @@
 
 
     // initialize the H/W composer
-    mHwc = new HWComposer();
+    mHwc = new HWComposer(mFlinger);
     if (mHwc->initCheck() == NO_ERROR) {
         mHwc->setFrameBuffer(mDisplay, mSurface);
     }
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.h b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
index cdf89fd..40a6f1e 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
@@ -95,6 +95,7 @@
     void init(uint32_t displayIndex) __attribute__((noinline));
     void fini() __attribute__((noinline));
 
+    sp<SurfaceFlinger> mFlinger;
     EGLDisplay      mDisplay;
     EGLSurface      mSurface;
     EGLContext      mContext;
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
index 30eb258..3ebc7b6 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardwareBase.h
@@ -37,7 +37,7 @@
 
                 ~DisplayHardwareBase();
 
-    // console managment
+    // console management
     void releaseScreen() const;
     void acquireScreen() const;
     bool isScreenAcquired() const;
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 4a3b20d..7d1bdf0 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -30,12 +30,14 @@
 #include <EGL/egl.h>
 
 #include "HWComposer.h"
+#include "SurfaceFlinger.h"
 
 namespace android {
 // ---------------------------------------------------------------------------
 
-HWComposer::HWComposer()
-    : mModule(0), mHwc(0), mList(0), mCapacity(0),
+HWComposer::HWComposer(const sp<SurfaceFlinger>& flinger)
+    : mFlinger(flinger),
+      mModule(0), mHwc(0), mList(0), mCapacity(0),
       mDpy(EGL_NO_DISPLAY), mSur(EGL_NO_SURFACE)
 {
     int err = hw_get_module(HWC_HARDWARE_MODULE_ID, &mModule);
@@ -44,6 +46,13 @@
         err = hwc_open(mModule, &mHwc);
         LOGE_IF(err, "%s device failed to initialize (%s)",
                 HWC_HARDWARE_COMPOSER, strerror(-err));
+        if (err == 0) {
+            if (mHwc->registerProcs) {
+                mCBContext.hwc = this;
+                mCBContext.procs.invalidate = &hook_invalidate;
+                mHwc->registerProcs(mHwc, &mCBContext.procs);
+            }
+        }
     }
 }
 
@@ -58,6 +67,14 @@
     return mHwc ? NO_ERROR : NO_INIT;
 }
 
+void HWComposer::hook_invalidate(struct hwc_procs* procs) {
+    reinterpret_cast<cb_context *>(procs)->hwc->invalidate();
+}
+
+void HWComposer::invalidate() {
+    mFlinger->signalEvent();
+}
+
 void HWComposer::setFrameBuffer(EGLDisplay dpy, EGLSurface sur) {
     mDpy = (hwc_display_t)dpy;
     mSur = (hwc_surface_t)sur;
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 5a9e9eb..983898a 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -24,16 +24,19 @@
 
 #include <hardware/hwcomposer.h>
 
+#include <utils/StrongPointer.h>
+
 namespace android {
 // ---------------------------------------------------------------------------
 
 class String8;
+class SurfaceFlinger;
 
 class HWComposer
 {
 public:
 
-    HWComposer();
+    HWComposer(const sp<SurfaceFlinger>& flinger);
     ~HWComposer();
 
     status_t initCheck() const;
@@ -60,12 +63,21 @@
     void dump(String8& out, char* scratch, size_t SIZE) const;
 
 private:
+    struct cb_context {
+        hwc_procs_t procs;
+        HWComposer* hwc;
+    };
+    static void hook_invalidate(struct hwc_procs* procs);
+    void invalidate();
+
+    sp<SurfaceFlinger>      mFlinger;
     hw_module_t const*      mModule;
     hwc_composer_device_t*  mHwc;
     hwc_layer_list_t*       mList;
     size_t                  mCapacity;
     hwc_display_t           mDpy;
     hwc_surface_t           mSur;
+    cb_context              mCBContext;
 };