Add SurfaceFlinger phase offset to configStore

Test: Manual
Bug: None
Change-Id: I64e07154903fedc40c153f4f53fb9a9aeae24dea
diff --git a/configstore/1.0/ISurfaceFlingerConfigs.hal b/configstore/1.0/ISurfaceFlingerConfigs.hal
index 4403a90..318590d 100644
--- a/configstore/1.0/ISurfaceFlingerConfigs.hal
+++ b/configstore/1.0/ISurfaceFlingerConfigs.hal
@@ -16,6 +16,29 @@
 package android.hardware.configstore@1.0;
 
 interface ISurfaceFlingerConfigs {
+    /*
+     * The following two methods define (respectively):
+     *
+     * - The phase offset between hardware vsync and when apps are woken up by the
+     *   Choreographer callback
+     * - The phase offset between hardware vsync and when SurfaceFlinger wakes up
+     *   to consume input
+     *
+     * Their values may be tuned to trade off between display pipeline latency (both
+     * overall latency and the lengths of the app --> SF and SF --> display phases)
+     * and frame delivery jitter (which typically manifests as "jank" or "jerkiness"
+     * while interacting with the device). The default values must produce a
+     * relatively low amount of jitter at the expense of roughly two frames of
+     * app --> display latency, and unless significant testing is performed to avoid
+     * increased display jitter (both manual investigation using systrace [1] and
+     * automated testing using dumpsys gfxinfo [2] are recommended), they should not
+     * be modified.
+     *
+     * [1] https://developer.android.com/studio/profile/systrace.html
+     * [2] https://developer.android.com/training/testing/performance.html
+     */
     vsyncEventPhaseOffsetNs() generates (OptionalInt64 value);
+    vsyncSfEventPhaseOffsetNs() generates (OptionalInt64 value);
+
     useTripleFramebuffer() generates (OptionalBool value);
 };
diff --git a/configstore/1.0/default/SurfaceFlingerConfigs.cpp b/configstore/1.0/default/SurfaceFlingerConfigs.cpp
index 5d62b15..f73ecb4 100644
--- a/configstore/1.0/default/SurfaceFlingerConfigs.cpp
+++ b/configstore/1.0/default/SurfaceFlingerConfigs.cpp
@@ -19,6 +19,16 @@
     return Void();
 }
 
+Return<void> SurfaceFlingerConfigs::vsyncSfEventPhaseOffsetNs(vsyncEventPhaseOffsetNs_cb _hidl_cb) {
+#ifdef SF_VSYNC_EVENT_PHASE_OFFSET_NS
+    _hidl_cb({true, SF_VSYNC_EVENT_PHASE_OFFSET_NS});
+    LOG(INFO) << "sfvsync event phase offset ns =  " << SF_VSYNC_EVENT_PHASE_OFFSET_NS;
+#else
+    _hidl_cb({false, 0});
+#endif
+    return Void();
+}
+
 Return<void> SurfaceFlingerConfigs::useTripleFramebuffer(useTripleFramebuffer_cb _hidl_cb) {
     bool value = false;
 #ifdef USE_TRIPLE_FRAMEBUFFER
diff --git a/configstore/1.0/default/SurfaceFlingerConfigs.h b/configstore/1.0/default/SurfaceFlingerConfigs.h
index c9652fc..bbb61d6 100644
--- a/configstore/1.0/default/SurfaceFlingerConfigs.h
+++ b/configstore/1.0/default/SurfaceFlingerConfigs.h
@@ -25,6 +25,7 @@
 struct SurfaceFlingerConfigs : public ISurfaceFlingerConfigs {
     // Methods from ::android::hardware::configstore::V1_0::ISurfaceFlingerConfigs follow.
     Return<void> vsyncEventPhaseOffsetNs(vsyncEventPhaseOffsetNs_cb _hidl_cb) override;
+    Return<void> vsyncSfEventPhaseOffsetNs(vsyncEventPhaseOffsetNs_cb _hidl_cb) override;
     Return<void> useTripleFramebuffer(useTripleFramebuffer_cb _hidl_cb) override;
 
     // Methods from ::android::hidl::base::V1_0::IBase follow.
diff --git a/configstore/1.0/default/surfaceflinger.mk b/configstore/1.0/default/surfaceflinger.mk
index 5a946f4..49314d7 100644
--- a/configstore/1.0/default/surfaceflinger.mk
+++ b/configstore/1.0/default/surfaceflinger.mk
@@ -5,6 +5,10 @@
     LOCAL_CFLAGS += -DVSYNC_EVENT_PHASE_OFFSET_NS=$(VSYNC_EVENT_PHASE_OFFSET_NS)
 endif
 
+ifneq ($(SF_VSYNC_EVENT_PHASE_OFFSET_NS),)
+    LOCAL_CFLAGS += -DSF_VSYNC_EVENT_PHASE_OFFSET_NS=$(SF_VSYNC_EVENT_PHASE_OFFSET_NS)
+endif
+
 ifeq ($(NUM_FRAMEBUFFER_SURFACE_BUFFERS),3)
     LOCAL_CFLAGS += -DUSE_TRIPLE_FRAMEBUFFER
 endif