diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index a4a6554..f440d29 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -315,7 +315,6 @@
 };
 
 struct DisplayDeviceState {
-    bool isValid() const { return type >= 0; }
     bool isVirtual() const { return type >= DisplayDevice::DISPLAY_VIRTUAL; }
 
     int32_t sequenceId = sNextSequenceId++;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 5acf2b8..f21c463 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3198,53 +3198,51 @@
     }
 }
 
-uint32_t SurfaceFlinger::setDisplayStateLocked(const DisplayState& s)
-{
-    ssize_t dpyIdx = mCurrentState.displays.indexOfKey(s.token);
-    if (dpyIdx < 0)
-        return 0;
+uint32_t SurfaceFlinger::setDisplayStateLocked(const DisplayState& s) {
+    const ssize_t index = mCurrentState.displays.indexOfKey(s.token);
+    if (index < 0) return 0;
 
     uint32_t flags = 0;
-    DisplayDeviceState& disp(mCurrentState.displays.editValueAt(dpyIdx));
-    if (disp.isValid()) {
-        const uint32_t what = s.what;
-        if (what & DisplayState::eSurfaceChanged) {
-            if (IInterface::asBinder(disp.surface) != IInterface::asBinder(s.surface)) {
-                disp.surface = s.surface;
-                flags |= eDisplayTransactionNeeded;
-            }
-        }
-        if (what & DisplayState::eLayerStackChanged) {
-            if (disp.layerStack != s.layerStack) {
-                disp.layerStack = s.layerStack;
-                flags |= eDisplayTransactionNeeded;
-            }
-        }
-        if (what & DisplayState::eDisplayProjectionChanged) {
-            if (disp.orientation != s.orientation) {
-                disp.orientation = s.orientation;
-                flags |= eDisplayTransactionNeeded;
-            }
-            if (disp.frame != s.frame) {
-                disp.frame = s.frame;
-                flags |= eDisplayTransactionNeeded;
-            }
-            if (disp.viewport != s.viewport) {
-                disp.viewport = s.viewport;
-                flags |= eDisplayTransactionNeeded;
-            }
-        }
-        if (what & DisplayState::eDisplaySizeChanged) {
-            if (disp.width != s.width) {
-                disp.width = s.width;
-                flags |= eDisplayTransactionNeeded;
-            }
-            if (disp.height != s.height) {
-                disp.height = s.height;
-                flags |= eDisplayTransactionNeeded;
-            }
+    DisplayDeviceState& state = mCurrentState.displays.editValueAt(index);
+
+    const uint32_t what = s.what;
+    if (what & DisplayState::eSurfaceChanged) {
+        if (IInterface::asBinder(state.surface) != IInterface::asBinder(s.surface)) {
+            state.surface = s.surface;
+            flags |= eDisplayTransactionNeeded;
         }
     }
+    if (what & DisplayState::eLayerStackChanged) {
+        if (state.layerStack != s.layerStack) {
+            state.layerStack = s.layerStack;
+            flags |= eDisplayTransactionNeeded;
+        }
+    }
+    if (what & DisplayState::eDisplayProjectionChanged) {
+        if (state.orientation != s.orientation) {
+            state.orientation = s.orientation;
+            flags |= eDisplayTransactionNeeded;
+        }
+        if (state.frame != s.frame) {
+            state.frame = s.frame;
+            flags |= eDisplayTransactionNeeded;
+        }
+        if (state.viewport != s.viewport) {
+            state.viewport = s.viewport;
+            flags |= eDisplayTransactionNeeded;
+        }
+    }
+    if (what & DisplayState::eDisplaySizeChanged) {
+        if (state.width != s.width) {
+            state.width = s.width;
+            flags |= eDisplayTransactionNeeded;
+        }
+        if (state.height != s.height) {
+            state.height = s.height;
+            flags |= eDisplayTransactionNeeded;
+        }
+    }
+
     return flags;
 }
 
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index 8d18d76..3be2ad0 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -245,6 +245,8 @@
 
     // The type for this display
     static constexpr DisplayDevice::DisplayType TYPE = type;
+    static_assert(TYPE != DisplayDevice::DISPLAY_ID_INVALID);
+
     static constexpr DisplayDevice::DisplayType DISPLAY_ID = displayId;
 
     // When creating native window surfaces for the framebuffer, whether those should be critical
@@ -385,11 +387,6 @@
                                  DisplayVariant<type, type, width, height, critical, Async::FALSE,
                                                 Secure::TRUE, GRALLOC_USAGE_PHYSICAL_DISPLAY>> {};
 
-// An invalid display
-using InvalidDisplayVariant =
-        DisplayVariant<DisplayDevice::DISPLAY_ID_INVALID, DisplayDevice::DISPLAY_ID_INVALID, 0, 0,
-                       Critical::FALSE, Async::FALSE, Secure::FALSE, 0>;
-
 // A primary display is a physical display that is critical
 using PrimaryDisplayVariant =
         PhysicalDisplayVariant<1001, DisplayDevice::DISPLAY_PRIMARY, 3840, 2160, Critical::TRUE>;
@@ -686,9 +683,7 @@
         Case<PrimaryDisplayVariant, WideColorNotSupportedVariant<PrimaryDisplayVariant>,
              HdrNotSupportedVariant<PrimaryDisplayVariant>,
              Cta861_3_PerFrameMetadataSupportVariant<PrimaryDisplayVariant>>;
-using InvalidDisplayCase = Case<InvalidDisplayVariant, WideColorSupportNotConfiguredVariant,
-                                NonHwcDisplayHdrSupportVariant,
-                                NoPerFrameMetadataSupportVariant<InvalidDisplayVariant>>;
+
 /* ------------------------------------------------------------------------
  *
  * SurfaceFlinger::onHotplugReceived
@@ -1834,40 +1829,6 @@
     EXPECT_FALSE(hasCurrentDisplayState(displayToken));
 }
 
-TEST_F(DisplayTransactionTest, setDisplayStateLockedDoesNothingWithInvalidDisplay) {
-    using Case = InvalidDisplayCase;
-
-    // --------------------------------------------------------------------
-    // Preconditions
-
-    // An invalid display is set up
-    auto display = Case::Display::makeFakeExistingDisplayInjector(this);
-    display.inject();
-
-    // The invalid display has some state
-    display.mutableCurrentDisplayState().layerStack = 654u;
-
-    // The requested display state tries to change the display state.
-    DisplayState state;
-    state.what = DisplayState::eLayerStackChanged;
-    state.token = display.token();
-    state.layerStack = 456;
-
-    // --------------------------------------------------------------------
-    // Invocation
-
-    uint32_t flags = mFlinger.setDisplayStateLocked(state);
-
-    // --------------------------------------------------------------------
-    // Postconditions
-
-    // The returned flags are empty
-    EXPECT_EQ(0u, flags);
-
-    // The current display layer stack value is unchanged.
-    EXPECT_EQ(654u, getCurrentDisplayState(display.token()).layerStack);
-}
-
 TEST_F(DisplayTransactionTest, setDisplayStateLockedDoesNothingWhenNoChanges) {
     using Case = SimplePrimaryDisplayCase;