diff --git a/libs/renderengine/include/renderengine/LayerSettings.h b/libs/renderengine/include/renderengine/LayerSettings.h
index bfb7465..ff4d112 100644
--- a/libs/renderengine/include/renderengine/LayerSettings.h
+++ b/libs/renderengine/include/renderengine/LayerSettings.h
@@ -194,18 +194,6 @@
             lhs.length == rhs.length && lhs.casterIsTranslucent == rhs.casterIsTranslucent;
 }
 
-static inline bool operator==(const BlurRegion& lhs, const BlurRegion& rhs) {
-    return lhs.alpha == rhs.alpha && lhs.cornerRadiusTL == rhs.cornerRadiusTL &&
-            lhs.cornerRadiusTR == rhs.cornerRadiusTR && lhs.cornerRadiusBL == rhs.cornerRadiusBL &&
-            lhs.cornerRadiusBR == rhs.cornerRadiusBR && lhs.blurRadius == rhs.blurRadius &&
-            lhs.left == rhs.left && lhs.top == rhs.top && lhs.right == rhs.right &&
-            lhs.bottom == rhs.bottom;
-}
-
-static inline bool operator!=(const BlurRegion& lhs, const BlurRegion& rhs) {
-    return !(lhs == rhs);
-}
-
 static inline bool operator==(const LayerSettings& lhs, const LayerSettings& rhs) {
     if (lhs.blurRegions.size() != rhs.blurRegions.size()) {
         return false;
diff --git a/libs/ui/include/ui/BlurRegion.h b/libs/ui/include/ui/BlurRegion.h
index 69a586e..a9ca369 100644
--- a/libs/ui/include/ui/BlurRegion.h
+++ b/libs/ui/include/ui/BlurRegion.h
@@ -20,6 +20,8 @@
 #include <iosfwd>
 #include <iostream>
 
+#include <math/HashCombine.h>
+
 namespace android {
 
 struct BlurRegion {
@@ -33,6 +35,16 @@
     int top;
     int right;
     int bottom;
+
+    inline bool operator==(const BlurRegion& other) const {
+        return blurRadius == other.blurRadius && cornerRadiusTL == other.cornerRadiusTL &&
+                cornerRadiusTR == other.cornerRadiusTR && cornerRadiusBL == other.cornerRadiusBL &&
+                cornerRadiusBR == other.cornerRadiusBR && alpha == other.alpha &&
+                left == other.left && top == other.top && right == other.right &&
+                bottom == other.bottom;
+    }
+
+    inline bool operator!=(const BlurRegion& other) const { return !(*this == other); }
 };
 
 static inline void PrintTo(const BlurRegion& blurRegion, ::std::ostream* os) {
@@ -50,4 +62,15 @@
     *os << "\n}";
 }
 
-} // namespace android
\ No newline at end of file
+} // namespace android
+
+namespace std {
+template <>
+struct hash<android::BlurRegion> {
+    size_t operator()(const android::BlurRegion& region) const {
+        return android::hashCombine(region.blurRadius, region.cornerRadiusTL, region.cornerRadiusTR,
+                                    region.cornerRadiusBL, region.cornerRadiusBR, region.alpha,
+                                    region.left, region.top, region.right, region.bottom);
+    }
+};
+} // namespace std
\ No newline at end of file
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
index 06f26eb..dc6eab4 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
@@ -110,6 +110,9 @@
     // CachedSet and punching a hole.
     bool requiresHolePunch() const;
 
+    // True if any constituent layer is configured to blur any layers behind.
+    bool hasBlurBehind() const;
+
     // Add a layer that will be drawn behind this one. ::render() will render a
     // hole in this CachedSet's buffer, allowing the supplied layer to peek
     // through. Must be called before ::render().
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
index 864251f..213c55e 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
@@ -20,6 +20,7 @@
 #include <compositionengine/impl/planner/CachedSet.h>
 #include <compositionengine/impl/planner/LayerState.h>
 
+#include <numeric>
 #include <vector>
 
 namespace android {
@@ -60,6 +61,73 @@
     bool mergeWithCachedSets(const std::vector<const LayerState*>& layers,
                              std::chrono::steady_clock::time_point now);
 
+    // A Run is a sequence of CachedSets, which is a candidate for flattening into a single
+    // CachedSet. Because it is wasteful to flatten 1 CachedSet, a Run must contain more than 1
+    // CachedSet
+    class Run {
+    public:
+        // A builder for a Run, to aid in construction
+        class Builder {
+        private:
+            std::vector<CachedSet>::const_iterator mStart;
+            std::vector<size_t> mLengths;
+            const CachedSet* mHolePunchCandidate = nullptr;
+
+        public:
+            // Initializes a Builder a CachedSet to start from.
+            // This start iterator must be an iterator for mLayers
+            void init(const std::vector<CachedSet>::const_iterator& start) {
+                mStart = start;
+                mLengths.push_back(start->getLayerCount());
+            }
+
+            // Appends a new CachedSet to the end of the run
+            // The provided length must be the size of the next sequential CachedSet in layers
+            void append(size_t length) { mLengths.push_back(length); }
+
+            // Sets the hole punch candidate for the Run.
+            void setHolePunchCandidate(const CachedSet* holePunchCandidate) {
+                mHolePunchCandidate = holePunchCandidate;
+            }
+
+            // Builds a Run instance, if a valid Run may be built.
+            std::optional<Run> validateAndBuild() {
+                if (mLengths.size() <= 1) {
+                    return std::nullopt;
+                }
+
+                return Run(mStart,
+                           std::reduce(mLengths.cbegin(), mLengths.cend(), 0u,
+                                       [](size_t left, size_t right) { return left + right; }),
+                           mHolePunchCandidate);
+            }
+
+            void reset() { *this = {}; }
+        };
+
+        // Gets the starting CachedSet of this run.
+        // This is an iterator into mLayers
+        const std::vector<CachedSet>::const_iterator& getStart() const { return mStart; }
+        // Gets the total number of layers encompassing this Run.
+        size_t getLayerLength() const { return mLength; }
+        // Gets the hole punch candidate for this Run.
+        const CachedSet* getHolePunchCandidate() const { return mHolePunchCandidate; }
+
+    private:
+        Run(std::vector<CachedSet>::const_iterator start, size_t length,
+            const CachedSet* holePunchCandidate)
+              : mStart(start), mLength(length), mHolePunchCandidate(holePunchCandidate) {}
+        const std::vector<CachedSet>::const_iterator mStart;
+        const size_t mLength;
+        const CachedSet* const mHolePunchCandidate;
+
+        friend class Builder;
+    };
+
+    std::vector<Run> findCandidateRuns(std::chrono::steady_clock::time_point now) const;
+
+    std::optional<Run> findBestRun(std::vector<Run>& runs) const;
+
     void buildCachedSets(std::chrono::steady_clock::time_point now);
 
     const bool mEnableHolePunch;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
index 3391273..fef0dfb 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
@@ -26,6 +26,7 @@
 #include <string>
 
 #include "DisplayHardware/Hal.h"
+#include "math/HashCombine.h"
 
 namespace std {
 template <typename T>
@@ -48,24 +49,26 @@
 
 // clang-format off
 enum class LayerStateField : uint32_t {
-    None            = 0u,
-    Id              = 1u << 0,
-    Name            = 1u << 1,
-    DisplayFrame    = 1u << 2,
-    SourceCrop      = 1u << 3,
-    BufferTransform = 1u << 4,
-    BlendMode       = 1u << 5,
-    Alpha           = 1u << 6,
-    LayerMetadata   = 1u << 7,
-    VisibleRegion   = 1u << 8,
-    Dataspace       = 1u << 9,
-    PixelFormat     = 1u << 10,
-    ColorTransform  = 1u << 11,
-    SurfaceDamage   = 1u << 12,
-    CompositionType = 1u << 13,
-    SidebandStream  = 1u << 14,
-    Buffer          = 1u << 15,
-    SolidColor      = 1u << 16,
+    None                  = 0u,
+    Id                    = 1u << 0,
+    Name                  = 1u << 1,
+    DisplayFrame          = 1u << 2,
+    SourceCrop            = 1u << 3,
+    BufferTransform       = 1u << 4,
+    BlendMode             = 1u << 5,
+    Alpha                 = 1u << 6,
+    LayerMetadata         = 1u << 7,
+    VisibleRegion         = 1u << 8,
+    Dataspace             = 1u << 9,
+    PixelFormat           = 1u << 10,
+    ColorTransform        = 1u << 11,
+    SurfaceDamage         = 1u << 12,
+    CompositionType       = 1u << 13,
+    SidebandStream        = 1u << 14,
+    Buffer                = 1u << 15,
+    SolidColor            = 1u << 16,
+    BackgroundBlurRadius  = 1u << 17,
+    BlurRegions           = 1u << 18,
 };
 // clang-format on
 
@@ -225,6 +228,9 @@
     const std::string& getName() const { return mName.get(); }
     Rect getDisplayFrame() const { return mDisplayFrame.get(); }
     const Region& getVisibleRegion() const { return mVisibleRegion.get(); }
+    bool hasBlurBehind() const {
+        return mBackgroundBlurRadius.get() > 0 || !mBlurRegions.get().empty();
+    }
     hardware::graphics::composer::hal::Composition getCompositionType() const {
         return mCompositionType.get();
     }
@@ -398,7 +404,45 @@
                             return std::vector<std::string>{stream.str()};
                         }};
 
-    static const constexpr size_t kNumNonUniqueFields = 14;
+    OutputLayerState<int32_t, LayerStateField::BackgroundBlurRadius> mBackgroundBlurRadius{
+            [](auto layer) {
+                return layer->getLayerFE().getCompositionState()->backgroundBlurRadius;
+            }};
+
+    using BlurRegionsState =
+            OutputLayerState<std::vector<BlurRegion>, LayerStateField::BlurRegions>;
+    BlurRegionsState mBlurRegions{[](auto layer) {
+                                      return layer->getLayerFE().getCompositionState()->blurRegions;
+                                  },
+                                  [](const std::vector<BlurRegion>& regions) {
+                                      std::vector<std::string> result;
+                                      for (const auto region : regions) {
+                                          std::string str;
+                                          base::StringAppendF(&str,
+                                                              "{radius=%du, cornerRadii=[%f, %f, "
+                                                              "%f, %f], alpha=%f, rect=[%d, "
+                                                              "%d, %d, %d]",
+                                                              region.blurRadius,
+                                                              region.cornerRadiusTL,
+                                                              region.cornerRadiusTR,
+                                                              region.cornerRadiusBL,
+                                                              region.cornerRadiusBR, region.alpha,
+                                                              region.left, region.top, region.right,
+                                                              region.bottom);
+                                          result.push_back(str);
+                                      }
+                                      return result;
+                                  },
+                                  BlurRegionsState::getDefaultEquals(),
+                                  [](const std::vector<BlurRegion>& regions) {
+                                      size_t hash = 0;
+                                      for (const auto& region : regions) {
+                                          android::hashCombineSingle(hash, region);
+                                      }
+                                      return hash;
+                                  }};
+
+    static const constexpr size_t kNumNonUniqueFields = 16;
 
     std::array<StateInterface*, kNumNonUniqueFields> getNonUniqueFields() {
         std::array<const StateInterface*, kNumNonUniqueFields> constFields =
@@ -413,10 +457,10 @@
 
     std::array<const StateInterface*, kNumNonUniqueFields> getNonUniqueFields() const {
         return {
-                &mDisplayFrame, &mSourceCrop,     &mBufferTransform, &mBlendMode,
-                &mAlpha,        &mLayerMetadata,  &mVisibleRegion,   &mOutputDataspace,
-                &mPixelFormat,  &mColorTransform, &mCompositionType, &mSidebandStream,
-                &mBuffer,       &mSolidColor,
+                &mDisplayFrame, &mSourceCrop,     &mBufferTransform,      &mBlendMode,
+                &mAlpha,        &mLayerMetadata,  &mVisibleRegion,        &mOutputDataspace,
+                &mPixelFormat,  &mColorTransform, &mCompositionType,      &mSidebandStream,
+                &mBuffer,       &mSolidColor,     &mBackgroundBlurRadius, &mBlurRegions,
         };
     }
 };
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
index 67854cf..63085cc 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
@@ -280,6 +280,11 @@
     return layerFE.hasRoundedCorners();
 }
 
+bool CachedSet::hasBlurBehind() const {
+    return std::any_of(mLayers.cbegin(), mLayers.cend(),
+                       [](const Layer& layer) { return layer.getState()->hasBlurBehind(); });
+}
+
 namespace {
 bool contains(const Rect& outer, const Rect& inner) {
     return outer.left <= inner.left && outer.right >= inner.right && outer.top <= inner.top &&
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
index 4453a99..294ec4b 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
@@ -327,85 +327,94 @@
     return true;
 }
 
-void Flattener::buildCachedSets(time_point now) {
-    struct Run {
-        Run(std::vector<CachedSet>::const_iterator start, size_t length)
-              : start(start), length(length) {}
-
-        std::vector<CachedSet>::const_iterator start;
-        size_t length;
-    };
-
-    if (mLayers.empty()) {
-        ALOGV("[%s] No layers found, returning", __func__);
-        return;
-    }
-
+std::vector<Flattener::Run> Flattener::findCandidateRuns(time_point now) const {
     std::vector<Run> runs;
     bool isPartOfRun = false;
-
-    // Keep track of the layer that follows a run. It's possible that we will
-    // render it with a hole-punch.
-    const CachedSet* holePunchLayer = nullptr;
+    Run::Builder builder;
+    bool firstLayer = true;
+    bool runHasFirstLayer = false;
 
     for (auto currentSet = mLayers.cbegin(); currentSet != mLayers.cend(); ++currentSet) {
-        if (now - currentSet->getLastUpdate() > kActiveLayerTimeout) {
-            // Layer is inactive
+        const bool layerIsInactive = now - currentSet->getLastUpdate() > kActiveLayerTimeout;
+        const bool layerHasBlur = currentSet->hasBlurBehind();
+        if (layerIsInactive && (firstLayer || runHasFirstLayer || !layerHasBlur)) {
             if (isPartOfRun) {
-                runs.back().length += currentSet->getLayerCount();
+                builder.append(currentSet->getLayerCount());
             } else {
                 // Runs can't start with a non-buffer layer
                 if (currentSet->getFirstLayer().getBuffer() == nullptr) {
                     ALOGV("[%s] Skipping initial non-buffer layer", __func__);
                 } else {
-                    runs.emplace_back(currentSet, currentSet->getLayerCount());
+                    builder.init(currentSet);
+                    if (firstLayer) {
+                        runHasFirstLayer = true;
+                    }
                     isPartOfRun = true;
                 }
             }
         } else if (isPartOfRun) {
-            // Runs must be at least 2 sets long or there's nothing to combine
-            if (runs.back().start->getLayerCount() == runs.back().length) {
-                runs.pop_back();
-            } else {
-                // The prior run contained at least two sets. Currently, we'll
-                // only possibly merge a single run, so only keep track of a
-                // holePunchLayer if this is the first run.
-                if (runs.size() == 1) {
-                    holePunchLayer = &(*currentSet);
-                }
-
-                // TODO(b/185114532: Break out of the loop? We may find more runs, but we
-                // won't do anything with them.
+            builder.setHolePunchCandidate(&(*currentSet));
+            if (auto run = builder.validateAndBuild(); run) {
+                runs.push_back(*run);
             }
 
+            runHasFirstLayer = false;
+            builder.reset();
             isPartOfRun = false;
         }
+
+        firstLayer = false;
     }
 
-    // Check for at least 2 sets one more time in case the set includes the last layer
-    if (isPartOfRun && runs.back().start->getLayerCount() == runs.back().length) {
-        runs.pop_back();
+    // If we're in the middle of a run at the end, we still need to validate and build it.
+    if (isPartOfRun) {
+        if (auto run = builder.validateAndBuild(); run) {
+            runs.push_back(*run);
+        }
     }
 
     ALOGV("[%s] Found %zu candidate runs", __func__, runs.size());
 
+    return runs;
+}
+
+std::optional<Flattener::Run> Flattener::findBestRun(std::vector<Flattener::Run>& runs) const {
     if (runs.empty()) {
+        return std::nullopt;
+    }
+
+    // TODO (b/181192467): Choose the best run, instead of just the first.
+    return runs[0];
+}
+
+void Flattener::buildCachedSets(time_point now) {
+    if (mLayers.empty()) {
+        ALOGV("[%s] No layers found, returning", __func__);
         return;
     }
 
-    mNewCachedSet.emplace(*runs[0].start);
+    std::vector<Run> runs = findCandidateRuns(now);
+
+    std::optional<Run> bestRun = findBestRun(runs);
+
+    if (!bestRun) {
+        return;
+    }
+
+    mNewCachedSet.emplace(*bestRun->getStart());
     mNewCachedSet->setLastUpdate(now);
-    auto currentSet = runs[0].start;
-    while (mNewCachedSet->getLayerCount() < runs[0].length) {
+    auto currentSet = bestRun->getStart();
+    while (mNewCachedSet->getLayerCount() < bestRun->getLayerLength()) {
         ++currentSet;
         mNewCachedSet->append(*currentSet);
     }
 
-    if (mEnableHolePunch && holePunchLayer && holePunchLayer->requiresHolePunch()) {
+    if (mEnableHolePunch && bestRun->getHolePunchCandidate() &&
+        bestRun->getHolePunchCandidate()->requiresHolePunch()) {
         // Add the pip layer to mNewCachedSet, but in a special way - it should
         // replace the buffer with a clear round rect.
-        mNewCachedSet->addHolePunchLayerIfFeasible(*holePunchLayer,
-                                                   runs[0].start == mLayers.cbegin());
+        mNewCachedSet->addHolePunchLayerIfFeasible(*bestRun->getHolePunchCandidate(),
+                                                   bestRun->getStart() == mLayers.cbegin());
     }
 
     // TODO(b/181192467): Actually compute new LayerState vector and corresponding hash for each run
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
index a39331c..488f64d 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
@@ -567,5 +567,30 @@
     }
 }
 
+TEST_F(CachedSetTest, hasBlurBehind) {
+    mTestLayers[1]->layerFECompositionState.backgroundBlurRadius = 1;
+    mTestLayers[1]->layerState->update(&mTestLayers[1]->outputLayer);
+    mTestLayers[2]->layerFECompositionState.blurRegions.push_back(
+            BlurRegion{1, 0, 0, 0, 0, 0, 0, 0, 0, 0});
+    mTestLayers[2]->layerState->update(&mTestLayers[2]->outputLayer);
+
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
+
+    CachedSet cachedSet1(layer1);
+    CachedSet cachedSet2(layer2);
+    CachedSet cachedSet3(layer3);
+
+    // Cached set 4 will consist of layers 1 and 2, which will contain a blur behind
+    CachedSet cachedSet4(layer1);
+    cachedSet4.addLayer(layer2.getState(), kStartTime);
+
+    EXPECT_FALSE(cachedSet1.hasBlurBehind());
+    EXPECT_TRUE(cachedSet2.hasBlurBehind());
+    EXPECT_TRUE(cachedSet3.hasBlurBehind());
+    EXPECT_TRUE(cachedSet4.hasBlurBehind());
+}
+
 } // namespace
 } // namespace android::compositionengine
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
index 25fab49..42096f3 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
@@ -642,5 +642,149 @@
     EXPECT_EQ(&mTestLayers[2]->outputLayer, peekThroughLayer1);
     EXPECT_EQ(peekThroughLayer1, peekThroughLayer2);
 }
+
+TEST_F(FlattenerTest, flattenLayers_flattensBlurBehindRunIfFirstRun) {
+    auto& layerState1 = mTestLayers[0]->layerState;
+
+    auto& layerState2 = mTestLayers[1]->layerState;
+    mTestLayers[1]->layerFECompositionState.backgroundBlurRadius = 1;
+    layerState2->update(&mTestLayers[1]->outputLayer);
+
+    auto& layerState3 = mTestLayers[2]->layerState;
+    const auto& overrideBuffer1 = layerState1->getOutputLayer()->getState().overrideInfo.buffer;
+    const auto& overrideBuffer2 = layerState2->getOutputLayer()->getState().overrideInfo.buffer;
+    const auto& overrideBuffer3 = layerState3->getOutputLayer()->getState().overrideInfo.buffer;
+
+    const std::vector<const LayerState*> layers = {
+            layerState1.get(),
+            layerState2.get(),
+            layerState3.get(),
+    };
+
+    initializeFlattener(layers);
+
+    // Mark the first two layers inactive, which contain the blur behind
+    mTime += 200ms;
+    layerState3->resetFramesSinceBufferUpdate();
+
+    // layers would be flattened but the buffer would not be overridden
+    EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Return(NO_ERROR));
+
+    initializeOverrideBuffer(layers);
+    EXPECT_EQ(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+
+    for (const auto layer : layers) {
+        EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
+    }
+
+    // the new flattened layer is replaced
+    initializeOverrideBuffer(layers);
+    EXPECT_NE(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    EXPECT_NE(nullptr, overrideBuffer1);
+    EXPECT_EQ(overrideBuffer1, overrideBuffer2);
+    EXPECT_EQ(nullptr, overrideBuffer3);
+}
+
+TEST_F(FlattenerTest, flattenLayers_doesNotFlattenBlurBehindRun) {
+    auto& layerState1 = mTestLayers[0]->layerState;
+
+    auto& layerState2 = mTestLayers[1]->layerState;
+    mTestLayers[1]->layerFECompositionState.backgroundBlurRadius = 1;
+    layerState2->update(&mTestLayers[1]->outputLayer);
+
+    auto& layerState3 = mTestLayers[2]->layerState;
+
+    const std::vector<const LayerState*> layers = {
+            layerState1.get(),
+            layerState2.get(),
+            layerState3.get(),
+    };
+
+    initializeFlattener(layers);
+
+    // Mark the last two layers inactive, which contains the blur layer, but does not contain the
+    // first layer
+    mTime += 200ms;
+    layerState1->resetFramesSinceBufferUpdate();
+
+    // layers would be flattened but the buffer would not be overridden
+    EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillRepeatedly(Return(NO_ERROR));
+
+    initializeOverrideBuffer(layers);
+    EXPECT_EQ(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+
+    for (const auto layer : layers) {
+        EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
+    }
+
+    // nothing is flattened because the last two frames cannot be cached due to containing a blur
+    // layer
+    initializeOverrideBuffer(layers);
+    EXPECT_EQ(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    for (const auto layer : layers) {
+        EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
+    }
+}
+
+TEST_F(FlattenerTest, flattenLayers_flattenSkipsLayerWithBlurBehind) {
+    auto& layerState1 = mTestLayers[0]->layerState;
+
+    auto& layerStateWithBlurBehind = mTestLayers[1]->layerState;
+    mTestLayers[1]->layerFECompositionState.backgroundBlurRadius = 1;
+    layerStateWithBlurBehind->update(&mTestLayers[1]->outputLayer);
+
+    auto& layerState3 = mTestLayers[2]->layerState;
+    auto& layerState4 = mTestLayers[3]->layerState;
+    const auto& overrideBuffer1 = layerState1->getOutputLayer()->getState().overrideInfo.buffer;
+    const auto& blurOverrideBuffer =
+            layerStateWithBlurBehind->getOutputLayer()->getState().overrideInfo.buffer;
+    const auto& overrideBuffer3 = layerState3->getOutputLayer()->getState().overrideInfo.buffer;
+    const auto& overrideBuffer4 = layerState4->getOutputLayer()->getState().overrideInfo.buffer;
+
+    const std::vector<const LayerState*> layers = {
+            layerState1.get(),
+            layerStateWithBlurBehind.get(),
+            layerState3.get(),
+            layerState4.get(),
+    };
+
+    initializeFlattener(layers);
+
+    // Mark the last three layers inactive, which contains the blur layer, but does not contain the
+    // first layer
+    mTime += 200ms;
+    layerState1->resetFramesSinceBufferUpdate();
+
+    // layers would be flattened but the buffer would not be overridden
+    EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Return(NO_ERROR));
+
+    initializeOverrideBuffer(layers);
+    EXPECT_EQ(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+
+    for (const auto layer : layers) {
+        EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
+    }
+
+    // the new flattened layer is replaced
+    initializeOverrideBuffer(layers);
+    EXPECT_NE(getNonBufferHash(layers),
+              mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
+    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    EXPECT_EQ(nullptr, overrideBuffer1);
+    EXPECT_EQ(nullptr, blurOverrideBuffer);
+    EXPECT_NE(nullptr, overrideBuffer3);
+    EXPECT_EQ(overrideBuffer3, overrideBuffer4);
+}
+
 } // namespace
 } // namespace android::compositionengine
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
index 948c850..a09ce14 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
@@ -58,6 +58,10 @@
 const GenericLayerMetadataEntry sMetadataValueTwo = GenericLayerMetadataEntry{
         .value = std::vector<uint8_t>({1, 3}),
 };
+const constexpr int32_t sBgBlurRadiusOne = 3;
+const constexpr int32_t sBgBlurRadiusTwo = 4;
+const BlurRegion sBlurRegionOne = BlurRegion{1, 2.f, 3.f, 4.f, 5.f, 6.f, 7, 8, 9, 10};
+const BlurRegion sBlurRegionTwo = BlurRegion{2, 3.f, 4.f, 5.f, 6.f, 7.f, 8, 9, 10, 11};
 
 struct LayerStateTest : public testing::Test {
     LayerStateTest() {
@@ -830,6 +834,114 @@
     EXPECT_TRUE(otherLayerState->compare(*mLayerState));
 }
 
+TEST_F(LayerStateTest, updateBackgroundBlur) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.backgroundBlurRadius = sBgBlurRadiusOne;
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+
+    mock::OutputLayer newOutputLayer;
+    mock::LayerFE newLayerFE;
+    LayerFECompositionState layerFECompositionStateTwo;
+    layerFECompositionStateTwo.backgroundBlurRadius = sBgBlurRadiusTwo;
+    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionState,
+                       layerFECompositionStateTwo);
+    Flags<LayerStateField> updates = mLayerState->update(&newOutputLayer);
+    EXPECT_EQ(Flags<LayerStateField>(LayerStateField::BackgroundBlurRadius), updates);
+}
+
+TEST_F(LayerStateTest, compareBackgroundBlur) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.backgroundBlurRadius = sBgBlurRadiusOne;
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+    mock::OutputLayer newOutputLayer;
+    mock::LayerFE newLayerFE;
+    LayerFECompositionState layerFECompositionStateTwo;
+    layerFECompositionStateTwo.backgroundBlurRadius = sBgBlurRadiusTwo;
+    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionState,
+                       layerFECompositionStateTwo);
+    auto otherLayerState = std::make_unique<LayerState>(&newOutputLayer);
+
+    verifyNonUniqueDifferingFields(*mLayerState, *otherLayerState,
+                                   LayerStateField::BackgroundBlurRadius);
+
+    EXPECT_TRUE(mLayerState->compare(*otherLayerState));
+    EXPECT_TRUE(otherLayerState->compare(*mLayerState));
+}
+
+TEST_F(LayerStateTest, updateBlurRegions) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.blurRegions.push_back(sBlurRegionOne);
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+
+    mock::OutputLayer newOutputLayer;
+    mock::LayerFE newLayerFE;
+    LayerFECompositionState layerFECompositionStateTwo;
+    layerFECompositionStateTwo.blurRegions.push_back(sBlurRegionTwo);
+    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionState,
+                       layerFECompositionStateTwo);
+    Flags<LayerStateField> updates = mLayerState->update(&newOutputLayer);
+    EXPECT_EQ(Flags<LayerStateField>(LayerStateField::BlurRegions), updates);
+}
+
+TEST_F(LayerStateTest, compareBlurRegions) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.blurRegions.push_back(sBlurRegionOne);
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+    mock::OutputLayer newOutputLayer;
+    mock::LayerFE newLayerFE;
+    LayerFECompositionState layerFECompositionStateTwo;
+    layerFECompositionStateTwo.blurRegions.push_back(sBlurRegionTwo);
+    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionState,
+                       layerFECompositionStateTwo);
+    auto otherLayerState = std::make_unique<LayerState>(&newOutputLayer);
+
+    verifyNonUniqueDifferingFields(*mLayerState, *otherLayerState, LayerStateField::BlurRegions);
+
+    EXPECT_TRUE(mLayerState->compare(*otherLayerState));
+    EXPECT_TRUE(otherLayerState->compare(*mLayerState));
+}
+
+TEST_F(LayerStateTest, hasBlurBehind_noBlur_returnsFalse) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+    EXPECT_FALSE(mLayerState->hasBlurBehind());
+}
+
+TEST_F(LayerStateTest, hasBlurBehind_withBackgroundBlur_returnsTrue) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.backgroundBlurRadius = sBgBlurRadiusOne;
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+    EXPECT_TRUE(mLayerState->hasBlurBehind());
+}
+
+TEST_F(LayerStateTest, hasBlurBehind_withBlurRegion_returnsTrue) {
+    OutputLayerCompositionState outputLayerCompositionState;
+    LayerFECompositionState layerFECompositionState;
+    layerFECompositionState.blurRegions.push_back(sBlurRegionOne);
+    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
+                       layerFECompositionState);
+    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
+    EXPECT_TRUE(mLayerState->hasBlurBehind());
+}
+
 TEST_F(LayerStateTest, dumpDoesNotCrash) {
     OutputLayerCompositionState outputLayerCompositionState;
     LayerFECompositionState layerFECompositionState;