libhwc2.1: Skip redundant onRefresh in histogramSample

DPU driver maintains always-on histogram engine state with up to
date histogram data. Therefore we don't have explicitly to trigger
onRefresh in case histogram configuration does not change.

Test: aidl_hist_client 500 500 1000 1999 340 340 344 POST 1000000
Bug: 261376040
Change-Id: I44824ee836adb66aeb214c371a11ed350d13b069
Signed-off-by: Leo Chen <yinchiuan@google.com>

1 files changed, 24 insertions, 5 deletions

diff --git a/libhwc2.1/pixel-display.cpp b/libhwc2.1/pixel-display.cpp
index fec7309..366945a 100644
--- a/libhwc2.1/pixel-display.cpp
+++ b/libhwc2.1/pixel-display.cpp
@@ -201,17 +201,36 @@ ndk::ScopedAStatus Display::setRefreshRateThrottle(int delayMs, int *_aidl_retur
 
 bool Display::runMediator(const RoiRect &roi, const Weight &weight, const HistogramPos &pos,
                             std::vector<char16_t> *histogrambuffer) {
-    if (mMediator.setRoiWeightThreshold(roi, weight, pos) != HistogramErrorCode::NONE) {
-        ALOGE("histogram error, SET_ROI_WEIGHT_THRESHOLD ERROR\n");
-        return false;
+    bool isConfigChanged;
+    histogram::HistogramMediator::HistogramConfig pendingConfig(roi, weight, pos);
+
+    {
+        std::unique_lock<std::mutex> lk(mMediator.mConfigMutex);
+        isConfigChanged = mMediator.mConfig != pendingConfig;
+
+        if (isConfigChanged &&
+            mMediator.setRoiWeightThreshold(roi, weight, pos) != HistogramErrorCode::NONE) {
+            ALOGE("histogram error, SET_ROI_WEIGHT_THRESHOLD ERROR\n");
+            return false;
+        }
+
+        mMediator.mConfig = pendingConfig;
     }
+
     if (!mMediator.histRequested() &&
         mMediator.requestHist() == HistogramErrorCode::ENABLE_HIST_ERROR) {
         ALOGE("histogram error, ENABLE_HIST ERROR\n");
     }
-    if (mMediator.getFrameCount() != mMediator.getSampleFrameCounter()) {
-        mDisplay->mDevice->onRefresh(mDisplay->mDisplayId); // DRM not busy & sampled frame changed
+
+    /*
+     * DPU driver maintains always-on histogram engine state with up to date histogram data.
+     * Therefore we don't have explicitly to trigger onRefresh in case histogram configuration
+     * does not change.
+     */
+    if (isConfigChanged) {
+        mDisplay->mDevice->onRefresh(mDisplay->mDisplayId);
     }
+
     if (mMediator.collectRoiLuma(histogrambuffer) != HistogramErrorCode::NONE) {
         ALOGE("histogram error, COLLECT_ROI_LUMA ERROR\n");
         return false;