Revert "Revert "libhwc2.1: wait for peak refresh rate before enabling LHBM""

This reverts commit 558f1a38e3a97629761fe013bf87151f66b356f4.

Reason for revert: reduce the FR by ag/18753590

Change-Id: I0865940dc2a1284669c2f1d82a0d5c6bd5fad6cc

4 files changed, 32 insertions, 0 deletions

diff --git a/libhwc2.1/libdevice/ExynosDisplay.h b/libhwc2.1/libdevice/ExynosDisplay.h
index 028798e..717ef88 100644
--- a/libhwc2.1/libdevice/ExynosDisplay.h
+++ b/libhwc2.1/libdevice/ExynosDisplay.h
@@ -1239,6 +1239,13 @@ class ExynosDisplay {
         // is the hint session both enabled and supported
         bool usePowerHintSession();
 
+        void setMinDisplayVsyncPeriod(uint32_t period) { mMinDisplayVsyncPeriod = period; }
+
+        bool isCurrentPeakRefreshRate(void) {
+            return ((mConfigRequestState == hwc_request_state_t::SET_CONFIG_STATE_NONE) &&
+                    (mVsyncPeriod == mMinDisplayVsyncPeriod));
+        }
+
     private:
         bool skipStaticLayerChanged(ExynosCompositionInfo& compositionInfo);
 
@@ -1253,6 +1260,9 @@ class ExynosDisplay {
         static constexpr float kHdrFullScreen = 0.5;
         uint32_t mHdrFullScrenAreaThreshold;
 
+        // vsync period of peak refresh rate
+        uint32_t mMinDisplayVsyncPeriod;
+
         /* Display hint to notify power hal */
         class PowerHalHintWorker : public Worker {
         public:
diff --git a/libhwc2.1/libdisplayinterface/ExynosDisplayDrmInterface.cpp b/libhwc2.1/libdisplayinterface/ExynosDisplayDrmInterface.cpp
index 7ee98a7..303033f 100644
--- a/libhwc2.1/libdisplayinterface/ExynosDisplayDrmInterface.cpp
+++ b/libhwc2.1/libdisplayinterface/ExynosDisplayDrmInterface.cpp
@@ -879,6 +879,7 @@ int32_t ExynosDisplayDrmInterface::getDisplayConfigs(
         /* key: (width<<32 | height) */
         std::map<uint64_t, uint32_t> groupIds;
         uint32_t groupId = 0;
+        uint32_t min_vsync_period = UINT_MAX;
 
         for (const DrmMode &mode : mDrmConnector->modes()) {
             displayConfigs_t configs;
@@ -899,11 +900,14 @@ int32_t ExynosDisplayDrmInterface::getDisplayConfigs(
             configs.Xdpi = mm_width ? (mode.h_display() * kUmPerInch) / mm_width : -1;
             // Dots per 1000 inches
             configs.Ydpi = mm_height ? (mode.v_display() * kUmPerInch) / mm_height : -1;
+            // find min vsync period
+            if (configs.vsyncPeriod <= min_vsync_period) min_vsync_period = configs.vsyncPeriod;
             mExynosDisplay->mDisplayConfigs.insert(std::make_pair(mode.id(), configs));
             ALOGD("config group(%d), w(%d), h(%d), vsync(%d), xdpi(%d), ydpi(%d)",
                     configs.groupId, configs.width, configs.height,
                     configs.vsyncPeriod, configs.Xdpi, configs.Ydpi);
         }
+        mExynosDisplay->setMinDisplayVsyncPeriod(min_vsync_period);
     }
 
     uint32_t num_modes = static_cast<uint32_t>(mDrmConnector->modes().size());
diff --git a/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.cpp b/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.cpp
index d20a313..633b1d7 100644
--- a/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.cpp
+++ b/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.cpp
@@ -495,6 +495,22 @@ int32_t ExynosPrimaryDisplay::SetCurrentPanelGammaSource(const DisplayType type,
 
 int32_t ExynosPrimaryDisplay::setLhbmState(bool enabled) {
     ATRACE_CALL();
+    if (enabled) {
+        ATRACE_NAME("wait for peak refresh rate");
+        for (int32_t i = 0; i <= kLhbmWaitForPeakRefreshRate; i++) {
+            if (!isCurrentPeakRefreshRate()) {
+                if (i == kLhbmWaitForPeakRefreshRate) {
+                    ALOGW("setLhbmState(on) wait for peak refresh rate timeout !");
+                    return TIMED_OUT;
+                }
+                usleep(mVsyncPeriod / 1000 + 1);
+            } else {
+                ALOGI_IF(i, "waited %d vsync to reach peak refresh rate", i);
+                break;
+            }
+        }
+    }
+
     requestLhbm(enabled);
     ALOGI("setLhbmState =%d", enabled);
 
diff --git a/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.h b/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.h
index e544749..c4d79ea 100644
--- a/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.h
+++ b/libhwc2.1/libmaindisplay/ExynosPrimaryDisplay.h
@@ -103,6 +103,8 @@ class ExynosPrimaryDisplay : public ExynosDisplay {
         bool mLhbmOn;
         bool mLhbmChanged;
         int32_t mFramesToReachLhbmPeakBrightness;
+        // wait num of vsync periods for peak refresh rate
+        static constexpr uint32_t kLhbmWaitForPeakRefreshRate = 10;
 
         std::mutex lhbm_mutex_;
         std::condition_variable lhbm_cond_;