Snap for 13197820 from 2e6071117a048dafe2eeb03d59d2b6adec371c35 to 25Q2-release

Change-Id: Ibb999ef775ccef8a56f7793f8c5b6e44b6c4fb97

21 files changed, 424 insertions, 21 deletions

diff --git a/include/input/DisplayTopologyGraph.h b/include/input/DisplayTopologyGraph.h
index 3ae865a33a..9fc080d6f8 100644
--- a/include/input/DisplayTopologyGraph.h
+++ b/include/input/DisplayTopologyGraph.h
@@ -46,6 +46,8 @@ struct DisplayTopologyAdjacentDisplay {
     DisplayTopologyPosition position;
     // The offset in DP of the adjacent display, relative to the source display.
     float offsetDp;
+
+    std::string dump() const;
 };
 
 /**
@@ -55,6 +57,9 @@ struct DisplayTopologyGraph {
     ui::LogicalDisplayId primaryDisplayId = ui::LogicalDisplayId::INVALID;
     std::unordered_map<ui::LogicalDisplayId, std::vector<DisplayTopologyAdjacentDisplay>> graph;
     std::unordered_map<ui::LogicalDisplayId, int> displaysDensity;
+
+    bool isValid() const;
+    std::string dump() const;
 };
 
 } // namespace android
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index b5fa321fc2..158c54886d 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -295,7 +295,6 @@ filegroup {
 cc_defaults {
     name: "libgui-defaults",
     defaults: ["libgui_bufferqueue-defaults"],
-    srcs: [":libgui-sources"],
     static_libs: [
         "libgui_aidl_static",
         "libgui_window_info_static",
@@ -319,6 +318,10 @@ cc_library_shared {
         "libgui-defaults",
     ],
 
+    srcs: [
+        ":libgui-sources",
+    ],
+
     export_static_lib_headers: [
         "libgui_aidl_static",
         "libgui_window_info_static",
diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index fa971426a7..1aae13c1f4 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -937,15 +937,22 @@ public:
           : Surface(igbp, controlledByApp, scHandle), mBbq(bbq) {}
 
     void allocateBuffers() override {
+        ATRACE_CALL();
         uint32_t reqWidth = mReqWidth ? mReqWidth : mUserWidth;
         uint32_t reqHeight = mReqHeight ? mReqHeight : mUserHeight;
         auto gbp = getIGraphicBufferProducer();
-        std::thread ([reqWidth, reqHeight, gbp=getIGraphicBufferProducer(),
-                      reqFormat=mReqFormat, reqUsage=mReqUsage] () {
+        std::thread allocateThread([reqWidth, reqHeight, gbp = getIGraphicBufferProducer(),
+                                    reqFormat = mReqFormat, reqUsage = mReqUsage]() {
+            if (com_android_graphics_libgui_flags_allocate_buffer_priority()) {
+                androidSetThreadName("allocateBuffers");
+                pid_t tid = gettid();
+                androidSetThreadPriority(tid, ANDROID_PRIORITY_DISPLAY);
+            }
+
             gbp->allocateBuffers(reqWidth, reqHeight,
                                  reqFormat, reqUsage);
-
-        }).detach();
+        });
+        allocateThread.detach();
     }
 
     status_t setFrameRate(float frameRate, int8_t compatibility,
diff --git a/libs/gui/BufferItemConsumer.cpp b/libs/gui/BufferItemConsumer.cpp
index 1585aae45c..4926ceb619 100644
--- a/libs/gui/BufferItemConsumer.cpp
+++ b/libs/gui/BufferItemConsumer.cpp
@@ -17,6 +17,7 @@
 //#define LOG_NDEBUG 0
 #define LOG_TAG "BufferItemConsumer"
 //#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+#include <utils/Errors.h>
 #include <utils/Log.h>
 
 #include <inttypes.h>
@@ -132,13 +133,36 @@ status_t BufferItemConsumer::acquireBuffer(BufferItem *item,
     return OK;
 }
 
+status_t BufferItemConsumer::attachBuffer(const sp<GraphicBuffer>& buffer) {
+    if (!buffer) {
+        BI_LOGE("BufferItemConsumer::attachBuffer no input buffer specified.");
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock _l(mMutex);
+
+    int slot = INVALID_BUFFER_SLOT;
+    status_t status = mConsumer->attachBuffer(&slot, buffer);
+    if (status != OK) {
+        BI_LOGE("BufferItemConsumer::attachBuffer unable to attach buffer %d", status);
+        return status;
+    }
+
+    mSlots[slot] = {
+            .mGraphicBuffer = buffer,
+            .mFence = nullptr,
+            .mFrameNumber = 0,
+    };
+
+    return OK;
+}
+
 status_t BufferItemConsumer::releaseBuffer(const BufferItem &item,
         const sp<Fence>& releaseFence) {
     Mutex::Autolock _l(mMutex);
     return releaseBufferSlotLocked(item.mSlot, item.mGraphicBuffer, releaseFence);
 }
 
-#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 status_t BufferItemConsumer::releaseBuffer(const sp<GraphicBuffer>& buffer,
                                            const sp<Fence>& releaseFence) {
     Mutex::Autolock _l(mMutex);
@@ -154,7 +178,6 @@ status_t BufferItemConsumer::releaseBuffer(const sp<GraphicBuffer>& buffer,
 
     return releaseBufferSlotLocked(slotIndex, buffer, releaseFence);
 }
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 status_t BufferItemConsumer::releaseBufferSlotLocked(int slotIndex, const sp<GraphicBuffer>& buffer,
                                                      const sp<Fence>& releaseFence) {
diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 270bfbdc64..4681c9ecbe 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -14,10 +14,6 @@
  * limitations under the License.
  */
 
-#include <inttypes.h>
-#include <pwd.h>
-#include <sys/types.h>
-
 #define LOG_TAG "BufferQueueConsumer"
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 //#define LOG_NDEBUG 0
@@ -48,6 +44,11 @@
 
 #include <com_android_graphics_libgui_flags.h>
 
+#include <inttypes.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <optional>
+
 namespace android {
 
 // Macros for include BufferQueueCore information in log messages
@@ -767,11 +768,15 @@ status_t BufferQueueConsumer::setMaxBufferCount(int bufferCount) {
     return NO_ERROR;
 }
 
+status_t BufferQueueConsumer::setMaxAcquiredBufferCount(int maxAcquiredBuffers) {
+    return setMaxAcquiredBufferCount(maxAcquiredBuffers, std::nullopt);
+}
+
 status_t BufferQueueConsumer::setMaxAcquiredBufferCount(
-        int maxAcquiredBuffers) {
+        int maxAcquiredBuffers, std::optional<OnBufferReleasedCallback> onBuffersReleasedCallback) {
     ATRACE_FORMAT("%s(%d)", __func__, maxAcquiredBuffers);
 
-    sp<IConsumerListener> listener;
+    std::optional<OnBufferReleasedCallback> callback;
     { // Autolock scope
         std::unique_lock<std::mutex> lock(mCore->mMutex);
 
@@ -833,13 +838,20 @@ status_t BufferQueueConsumer::setMaxAcquiredBufferCount(
         BQ_LOGV("setMaxAcquiredBufferCount: %d", maxAcquiredBuffers);
         mCore->mMaxAcquiredBufferCount = maxAcquiredBuffers;
         VALIDATE_CONSISTENCY();
-        if (delta < 0 && mCore->mBufferReleasedCbEnabled) {
-            listener = mCore->mConsumerListener;
+        if (delta < 0) {
+            if (onBuffersReleasedCallback) {
+                callback = std::move(onBuffersReleasedCallback);
+            } else if (mCore->mBufferReleasedCbEnabled) {
+                callback = [listener = mCore->mConsumerListener]() {
+                    listener->onBuffersReleased();
+                };
+            }
         }
     }
+
     // Call back without lock held
-    if (listener != nullptr) {
-        listener->onBuffersReleased();
+    if (callback) {
+        (*callback)();
     }
 
     return NO_ERROR;
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index 117a362661..5b89c6e17e 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -264,7 +264,10 @@ void ConsumerBase::onFrameReplaced(const BufferItem &item) {
 
 void ConsumerBase::onBuffersReleased() {
     Mutex::Autolock lock(mMutex);
+    onBuffersReleasedLocked();
+}
 
+void ConsumerBase::onBuffersReleasedLocked() {
     CB_LOGV("onBuffersReleased");
 
     if (mAbandoned) {
@@ -481,7 +484,8 @@ status_t ConsumerBase::setMaxAcquiredBufferCount(int maxAcquiredBuffers) {
         CB_LOGE("setMaxAcquiredBufferCount: ConsumerBase is abandoned!");
         return NO_INIT;
     }
-    return mConsumer->setMaxAcquiredBufferCount(maxAcquiredBuffers);
+    return mConsumer->setMaxAcquiredBufferCount(maxAcquiredBuffers,
+                                                {[this]() { onBuffersReleasedLocked(); }});
 }
 
 status_t ConsumerBase::setConsumerIsProtected(bool isProtected) {
diff --git a/libs/gui/include/gui/BufferItemConsumer.h b/libs/gui/include/gui/BufferItemConsumer.h
index 0bfa7b222e..fc31f4636c 100644
--- a/libs/gui/include/gui/BufferItemConsumer.h
+++ b/libs/gui/include/gui/BufferItemConsumer.h
@@ -96,6 +96,14 @@ class BufferItemConsumer: public ConsumerBase
     status_t acquireBuffer(BufferItem* item, nsecs_t presentWhen,
             bool waitForFence = true);
 
+    // Transfer ownership of a buffer to the BufferQueue. On NO_ERROR, the buffer
+    // is considered as if it were acquired. Buffer must not be null.
+    //
+    // Returns
+    //  - BAD_VALUE if buffer is null
+    //  - INVALID_OPERATION if too many buffers have already been acquired
+    status_t attachBuffer(const sp<GraphicBuffer>& buffer);
+
     // Returns an acquired buffer to the queue, allowing it to be reused. Since
     // only a fixed number of buffers may be acquired at a time, old buffers
     // must be released by calling releaseBuffer to ensure new buffers can be
@@ -105,10 +113,8 @@ class BufferItemConsumer: public ConsumerBase
     status_t releaseBuffer(const BufferItem &item,
             const sp<Fence>& releaseFence = Fence::NO_FENCE);
 
-#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
     status_t releaseBuffer(const sp<GraphicBuffer>& buffer,
                            const sp<Fence>& releaseFence = Fence::NO_FENCE);
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 protected:
 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
diff --git a/libs/gui/include/gui/BufferQueueConsumer.h b/libs/gui/include/gui/BufferQueueConsumer.h
index ab1231ad6b..ba6a6a73f4 100644
--- a/libs/gui/include/gui/BufferQueueConsumer.h
+++ b/libs/gui/include/gui/BufferQueueConsumer.h
@@ -122,7 +122,10 @@ public:
     // setMaxAcquiredBufferCount sets the maximum number of buffers that can
     // be acquired by the consumer at one time (default 1).  This call will
     // fail if a producer is connected to the BufferQueue.
-    virtual status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers);
+    virtual status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers) override;
+    virtual status_t setMaxAcquiredBufferCount(
+            int maxAcquiredBuffers,
+            std::optional<OnBufferReleasedCallback> onBuffersReleasedCallback) override;
 
     // setConsumerName sets the name used in logging
     status_t setConsumerName(const String8& name) override;
diff --git a/libs/gui/include/gui/ConsumerBase.h b/libs/gui/include/gui/ConsumerBase.h
index fd67f09a4a..d2215ef7e6 100644
--- a/libs/gui/include/gui/ConsumerBase.h
+++ b/libs/gui/include/gui/ConsumerBase.h
@@ -191,6 +191,8 @@ protected:
 #endif
     virtual int getSlotForBufferLocked(const sp<GraphicBuffer>& buffer);
 
+    virtual void onBuffersReleasedLocked();
+
     virtual status_t detachBufferLocked(int slotIndex);
 
     // freeBufferLocked frees up the given buffer slot.  If the slot has been
diff --git a/libs/gui/include/gui/IGraphicBufferConsumer.h b/libs/gui/include/gui/IGraphicBufferConsumer.h
index 8272a591da..8066b070fb 100644
--- a/libs/gui/include/gui/IGraphicBufferConsumer.h
+++ b/libs/gui/include/gui/IGraphicBufferConsumer.h
@@ -243,6 +243,9 @@ public:
     // maxAcquiredBuffers must be (inclusive) between 1 and MAX_MAX_ACQUIRED_BUFFERS. It also cannot
     // cause the maxBufferCount value to be exceeded.
     //
+    // If called with onBuffersReleasedCallback, that call back will be called in lieu of
+    // IConsumerListener::onBuffersReleased.
+    //
     // Return of a value other than NO_ERROR means an error has occurred:
     // * NO_INIT - the BufferQueue has been abandoned
     // * BAD_VALUE - one of the below conditions occurred:
@@ -253,6 +256,11 @@ public:
     // * INVALID_OPERATION - attempting to call this after a producer connected.
     virtual status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers) = 0;
 
+    using OnBufferReleasedCallback = std::function<void(void)>;
+    virtual status_t setMaxAcquiredBufferCount(
+            int maxAcquiredBuffers,
+            std::optional<OnBufferReleasedCallback> onBuffersReleasedCallback) = 0;
+
     // setConsumerName sets the name used in logging
     virtual status_t setConsumerName(const String8& name) = 0;
 
diff --git a/libs/gui/include/gui/mock/GraphicBufferConsumer.h b/libs/gui/include/gui/mock/GraphicBufferConsumer.h
index 24d26b12a1..18a7e12fa7 100644
--- a/libs/gui/include/gui/mock/GraphicBufferConsumer.h
+++ b/libs/gui/include/gui/mock/GraphicBufferConsumer.h
@@ -47,6 +47,7 @@ public:
     MOCK_METHOD2(setDefaultBufferSize, status_t(uint32_t, uint32_t));
     MOCK_METHOD1(setMaxBufferCount, status_t(int));
     MOCK_METHOD1(setMaxAcquiredBufferCount, status_t(int));
+    MOCK_METHOD2(setMaxAcquiredBufferCount, status_t(int, std::optional<OnBufferReleasedCallback>));
     MOCK_METHOD1(setConsumerName, status_t(const String8&));
     MOCK_METHOD1(setDefaultBufferFormat, status_t(PixelFormat));
     MOCK_METHOD1(setDefaultBufferDataSpace, status_t(android_dataspace));
diff --git a/libs/gui/libgui_flags.aconfig b/libs/gui/libgui_flags.aconfig
index 534f05e987..2c3222dd82 100644
--- a/libs/gui/libgui_flags.aconfig
+++ b/libs/gui/libgui_flags.aconfig
@@ -142,3 +142,14 @@ flag {
   bug: "340934031"
   is_fixed_read_only: true
 } # wb_media_migration
+
+flag {
+  name: "allocate_buffer_priority"
+  namespace: "wear_system_health"
+  description: "Boost priority for buffer allocation"
+  bug: "399701430"
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+  is_fixed_read_only: true
+} # allocate_buffer_priority
diff --git a/libs/gui/tests/Android.bp b/libs/gui/tests/Android.bp
index e20345dd1a..308b2ab1c8 100644
--- a/libs/gui/tests/Android.bp
+++ b/libs/gui/tests/Android.bp
@@ -100,6 +100,7 @@ cc_test {
         "android.hardware.configstore-utils",
         "libSurfaceFlingerProp",
         "libGLESv1_CM",
+        "libgui",
         "libgui_test_server_aidl-cpp",
         "libinput",
         "libnativedisplay",
diff --git a/libs/gui/tests/BufferItemConsumer_test.cpp b/libs/gui/tests/BufferItemConsumer_test.cpp
index b980f882ff..80eea267bf 100644
--- a/libs/gui/tests/BufferItemConsumer_test.cpp
+++ b/libs/gui/tests/BufferItemConsumer_test.cpp
@@ -24,6 +24,7 @@
 #include <gui/Surface.h>
 #include <ui/BufferQueueDefs.h>
 #include <ui/GraphicBuffer.h>
+#include <utils/Errors.h>
 
 #include <unordered_set>
 
@@ -235,6 +236,38 @@ TEST_F(BufferItemConsumerTest, TriggerBufferFreed_DeleteBufferItemConsumer) {
     ASSERT_EQ(1, GetFreedBufferCount());
 }
 
+TEST_F(BufferItemConsumerTest, ResizeAcquireCount) {
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers + 1));
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers + 2));
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers - 1));
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers - 2));
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers + 1));
+    EXPECT_EQ(OK, mBIC->setMaxAcquiredBufferCount(kMaxLockedBuffers - 1));
+}
+
+TEST_F(BufferItemConsumerTest, AttachBuffer) {
+    ASSERT_EQ(OK, mBIC->setMaxAcquiredBufferCount(1));
+
+    int slot;
+    DequeueBuffer(&slot);
+    QueueBuffer(slot);
+    AcquireBuffer(&slot);
+
+    sp<GraphicBuffer> newBuffer1 = sp<GraphicBuffer>::make(kWidth, kHeight, kFormat, kUsage);
+    sp<GraphicBuffer> newBuffer2 = sp<GraphicBuffer>::make(kWidth, kHeight, kFormat, kUsage);
+
+    // For some reason, you can attach an extra buffer?
+    // b/400973991 to investigate
+    EXPECT_EQ(OK, mBIC->attachBuffer(newBuffer1));
+    EXPECT_EQ(INVALID_OPERATION, mBIC->attachBuffer(newBuffer2));
+
+    ReleaseBuffer(slot);
+
+    EXPECT_EQ(OK, mBIC->attachBuffer(newBuffer2));
+    EXPECT_EQ(OK, mBIC->releaseBuffer(newBuffer1, Fence::NO_FENCE));
+    EXPECT_EQ(OK, mBIC->releaseBuffer(newBuffer2, Fence::NO_FENCE));
+}
+
 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 // Test that delete BufferItemConsumer triggers onBufferFreed.
 TEST_F(BufferItemConsumerTest, DetachBufferWithBuffer) {
diff --git a/libs/input/Android.bp b/libs/input/Android.bp
index dc038789b9..52e0276cad 100644
--- a/libs/input/Android.bp
+++ b/libs/input/Android.bp
@@ -225,6 +225,7 @@ cc_library {
     srcs: [
         "AccelerationCurve.cpp",
         "CoordinateFilter.cpp",
+        "DisplayTopologyGraph.cpp",
         "Input.cpp",
         "InputConsumer.cpp",
         "InputConsumerNoResampling.cpp",
diff --git a/libs/input/DisplayTopologyGraph.cpp b/libs/input/DisplayTopologyGraph.cpp
new file mode 100644
index 0000000000..934f2e8135
--- /dev/null
+++ b/libs/input/DisplayTopologyGraph.cpp
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "DisplayTopologyValidator"
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <ftl/enum.h>
+#include <input/DisplayTopologyGraph.h>
+#include <input/PrintTools.h>
+#include <ui/LogicalDisplayId.h>
+
+#include <algorithm>
+
+#define INDENT "  "
+
+namespace android {
+
+namespace {
+
+DisplayTopologyPosition getOppositePosition(DisplayTopologyPosition position) {
+    switch (position) {
+        case DisplayTopologyPosition::LEFT:
+            return DisplayTopologyPosition::RIGHT;
+        case DisplayTopologyPosition::TOP:
+            return DisplayTopologyPosition::BOTTOM;
+        case DisplayTopologyPosition::RIGHT:
+            return DisplayTopologyPosition::LEFT;
+        case DisplayTopologyPosition::BOTTOM:
+            return DisplayTopologyPosition::TOP;
+    }
+}
+
+bool validatePrimaryDisplay(const android::DisplayTopologyGraph& displayTopologyGraph) {
+    return displayTopologyGraph.primaryDisplayId != ui::LogicalDisplayId::INVALID &&
+            displayTopologyGraph.graph.contains(displayTopologyGraph.primaryDisplayId);
+}
+
+bool validateTopologyGraph(const android::DisplayTopologyGraph& displayTopologyGraph) {
+    for (const auto& [sourceDisplay, adjacentDisplays] : displayTopologyGraph.graph) {
+        for (const DisplayTopologyAdjacentDisplay& adjacentDisplay : adjacentDisplays) {
+            const auto adjacentGraphIt = displayTopologyGraph.graph.find(adjacentDisplay.displayId);
+            if (adjacentGraphIt == displayTopologyGraph.graph.end()) {
+                LOG(ERROR) << "Missing adjacent display in topology graph: "
+                           << adjacentDisplay.displayId << " for source " << sourceDisplay;
+                return false;
+            }
+            const auto reverseEdgeIt =
+                    std::find_if(adjacentGraphIt->second.begin(), adjacentGraphIt->second.end(),
+                                 [sourceDisplay](const DisplayTopologyAdjacentDisplay&
+                                                         reverseAdjacentDisplay) {
+                                     return sourceDisplay == reverseAdjacentDisplay.displayId;
+                                 });
+            if (reverseEdgeIt == adjacentGraphIt->second.end()) {
+                LOG(ERROR) << "Missing reverse edge in topology graph for: " << sourceDisplay
+                           << " -> " << adjacentDisplay.displayId;
+                return false;
+            }
+            DisplayTopologyPosition expectedPosition =
+                    getOppositePosition(adjacentDisplay.position);
+            if (reverseEdgeIt->position != expectedPosition) {
+                LOG(ERROR) << "Unexpected reverse edge for: " << sourceDisplay << " -> "
+                           << adjacentDisplay.displayId
+                           << " expected position: " << ftl::enum_string(expectedPosition)
+                           << " actual " << ftl::enum_string(reverseEdgeIt->position);
+                return false;
+            }
+            if (reverseEdgeIt->offsetDp != -adjacentDisplay.offsetDp) {
+                LOG(ERROR) << "Unexpected reverse edge offset: " << sourceDisplay << " -> "
+                           << adjacentDisplay.displayId
+                           << " expected offset: " << -adjacentDisplay.offsetDp << " actual "
+                           << reverseEdgeIt->offsetDp;
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+bool validateDensities(const android::DisplayTopologyGraph& displayTopologyGraph) {
+    for (const auto& [sourceDisplay, adjacentDisplays] : displayTopologyGraph.graph) {
+        if (!displayTopologyGraph.displaysDensity.contains(sourceDisplay)) {
+            LOG(ERROR) << "Missing density value in topology graph for display: " << sourceDisplay;
+            return false;
+        }
+    }
+    return true;
+}
+
+std::string logicalDisplayIdToString(const ui::LogicalDisplayId& displayId) {
+    return base::StringPrintf("displayId(%d)", displayId.val());
+}
+
+std::string adjacentDisplayToString(const DisplayTopologyAdjacentDisplay& adjacentDisplay) {
+    return adjacentDisplay.dump();
+}
+
+std::string adjacentDisplayVectorToString(
+        const std::vector<DisplayTopologyAdjacentDisplay>& adjacentDisplays) {
+    return dumpVector(adjacentDisplays, adjacentDisplayToString);
+}
+
+} // namespace
+
+std::string DisplayTopologyAdjacentDisplay::dump() const {
+    std::string dump;
+    dump += base::StringPrintf("DisplayTopologyAdjacentDisplay: {displayId: %d, position: %s, "
+                               "offsetDp: %f}",
+                               displayId.val(), ftl::enum_string(position).c_str(), offsetDp);
+    return dump;
+}
+
+bool DisplayTopologyGraph::isValid() const {
+    return validatePrimaryDisplay(*this) && validateTopologyGraph(*this) &&
+            validateDensities(*this);
+}
+
+std::string DisplayTopologyGraph::dump() const {
+    std::string dump;
+    dump += base::StringPrintf("PrimaryDisplayId: %d\n", primaryDisplayId.val());
+    dump += base::StringPrintf("TopologyGraph:\n");
+    dump += addLinePrefix(dumpMap(graph, logicalDisplayIdToString, adjacentDisplayVectorToString),
+                          INDENT);
+    dump += "\n";
+    dump += base::StringPrintf("DisplaysDensity:\n");
+    dump += addLinePrefix(dumpMap(displaysDensity, logicalDisplayIdToString), INDENT);
+    dump += "\n";
+    return dump;
+}
+
+} // namespace android
diff --git a/libs/input/input_flags.aconfig b/libs/input/input_flags.aconfig
index 1c0c9e7252..983bbdee6e 100644
--- a/libs/input/input_flags.aconfig
+++ b/libs/input/input_flags.aconfig
@@ -239,3 +239,13 @@ flag {
     purpose: PURPOSE_BUGFIX
   }
 }
+
+flag {
+  name: "enable_display_topology_validation"
+  namespace: "input"
+  description: "Set to true to enable display topology validation"
+  bug: "401219231"
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+}
diff --git a/services/inputflinger/PointerChoreographer.cpp b/services/inputflinger/PointerChoreographer.cpp
index f8ab830d2d..98f0f346df 100644
--- a/services/inputflinger/PointerChoreographer.cpp
+++ b/services/inputflinger/PointerChoreographer.cpp
@@ -31,6 +31,7 @@
 #include "PointerChoreographer.h"
 
 #define INDENT "  "
+#define INDENT2 "    "
 
 namespace android {
 
@@ -647,6 +648,8 @@ void PointerChoreographer::dump(std::string& dump) {
         std::string pointerControllerDump = addLinePrefix(drawingTabletController->dump(), INDENT);
         dump += INDENT + std::to_string(deviceId) + " : " + pointerControllerDump;
     }
+    dump += INDENT "DisplayTopologyGraph:\n";
+    dump += addLinePrefix(mTopology.dump(), INDENT2);
     dump += "\n";
 }
 
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index ef50fc0036..888fcfb592 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -5222,6 +5222,11 @@ std::string InputDispatcher::DispatcherWindowInfo::dumpDisplayAndWindowInfo() co
     } else {
         dump += "Displays: <none>\n";
     }
+    dump += StringPrintf("mMaximumObscuringOpacityForTouch: %f\n",
+                         mMaximumObscuringOpacityForTouch);
+    dump += "DisplayTopologyGraph:\n";
+    dump += addLinePrefix(mTopology.dump(), INDENT);
+    dump += "\n";
     return dump;
 }
 
diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 18d47f648b..677cf1e6c4 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -52,6 +52,7 @@ cc_test {
         "AnrTracker_test.cpp",
         "CapturedTouchpadEventConverter_test.cpp",
         "CursorInputMapper_test.cpp",
+        "DisplayTopologyGraph_test.cpp",
         "EventHub_test.cpp",
         "FakeEventHub.cpp",
         "FakeInputReaderPolicy.cpp",
diff --git a/services/inputflinger/tests/DisplayTopologyGraph_test.cpp b/services/inputflinger/tests/DisplayTopologyGraph_test.cpp
new file mode 100644
index 0000000000..fd2f21c4cb
--- /dev/null
+++ b/services/inputflinger/tests/DisplayTopologyGraph_test.cpp
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include <input/DisplayTopologyGraph.h>
+
+#include <string>
+#include <string_view>
+#include <tuple>
+
+namespace android {
+
+namespace {
+
+constexpr ui::LogicalDisplayId DISPLAY_ID_1{1};
+constexpr ui::LogicalDisplayId DISPLAY_ID_2{2};
+constexpr int DENSITY_MEDIUM = 160;
+
+} // namespace
+
+using DisplayTopologyGraphTestFixtureParam =
+        std::tuple<std::string_view /*name*/, DisplayTopologyGraph, bool /*isValid*/>;
+
+class DisplayTopologyGraphTestFixture
+      : public testing::Test,
+        public testing::WithParamInterface<DisplayTopologyGraphTestFixtureParam> {};
+
+TEST_P(DisplayTopologyGraphTestFixture, DisplayTopologyGraphTest) {
+    const auto& [_, displayTopology, isValid] = GetParam();
+    EXPECT_EQ(isValid, displayTopology.isValid());
+}
+
+INSTANTIATE_TEST_SUITE_P(
+        DisplayTopologyGraphTest, DisplayTopologyGraphTestFixture,
+        testing::Values(
+                std::make_tuple(
+                        "InvalidPrimaryDisplay",
+                        DisplayTopologyGraph{.primaryDisplayId = ui::LogicalDisplayId::INVALID,
+                                             .graph = {},
+                                             .displaysDensity = {}},
+                        false),
+                std::make_tuple("PrimaryDisplayNotInGraph",
+                                DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                                     .graph = {},
+                                                     .displaysDensity = {}},
+                                false),
+                std::make_tuple("DisplayDensityMissing",
+                                DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                                     .graph = {{DISPLAY_ID_1, {}}},
+                                                     .displaysDensity = {}},
+                                false),
+                std::make_tuple("ValidSingleDisplayTopology",
+                                DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                                     .graph = {{DISPLAY_ID_1, {}}},
+                                                     .displaysDensity = {{DISPLAY_ID_1,
+                                                                          DENSITY_MEDIUM}}},
+                                true),
+                std::make_tuple(
+                        "MissingReverseEdge",
+                        DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                             .graph = {{DISPLAY_ID_1,
+                                                        {{DISPLAY_ID_2,
+                                                          DisplayTopologyPosition::TOP, 0}}}},
+                                             .displaysDensity = {{DISPLAY_ID_1, DENSITY_MEDIUM},
+                                                                 {DISPLAY_ID_2, DENSITY_MEDIUM}}},
+                        false),
+                std::make_tuple(
+                        "IncorrectReverseEdgeDirection",
+                        DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                             .graph = {{DISPLAY_ID_1,
+                                                        {{DISPLAY_ID_2,
+                                                          DisplayTopologyPosition::TOP, 0}}},
+                                                       {DISPLAY_ID_2,
+                                                        {{DISPLAY_ID_1,
+                                                          DisplayTopologyPosition::TOP, 0}}}},
+                                             .displaysDensity = {{DISPLAY_ID_1, DENSITY_MEDIUM},
+                                                                 {DISPLAY_ID_2, DENSITY_MEDIUM}}},
+                        false),
+                std::make_tuple(
+                        "IncorrectReverseEdgeOffset",
+                        DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                             .graph = {{DISPLAY_ID_1,
+                                                        {{DISPLAY_ID_2,
+                                                          DisplayTopologyPosition::TOP, 10}}},
+                                                       {DISPLAY_ID_2,
+                                                        {{DISPLAY_ID_1,
+                                                          DisplayTopologyPosition::BOTTOM, 20}}}},
+                                             .displaysDensity = {{DISPLAY_ID_1, DENSITY_MEDIUM},
+                                                                 {DISPLAY_ID_2, DENSITY_MEDIUM}}},
+                        false),
+                std::make_tuple(
+                        "ValidMultiDisplayTopology",
+                        DisplayTopologyGraph{.primaryDisplayId = DISPLAY_ID_1,
+                                             .graph = {{DISPLAY_ID_1,
+                                                        {{DISPLAY_ID_2,
+                                                          DisplayTopologyPosition::TOP, 10}}},
+                                                       {DISPLAY_ID_2,
+                                                        {{DISPLAY_ID_1,
+                                                          DisplayTopologyPosition::BOTTOM, -10}}}},
+                                             .displaysDensity = {{DISPLAY_ID_1, DENSITY_MEDIUM},
+                                                                 {DISPLAY_ID_2, DENSITY_MEDIUM}}},
+                        true)),
+        [](const testing::TestParamInfo<DisplayTopologyGraphTestFixtureParam>& p) {
+            return std::string{std::get<0>(p.param)};
+        });
+
+} // namespace android