diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 6e33272..3e12db6 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -109,7 +109,6 @@
 void Scheduler::setPacesetterDisplay(std::optional<PhysicalDisplayId> pacesetterIdOpt) {
     demotePacesetterDisplay();
 
-    std::scoped_lock lock(mDisplayLock);
     promotePacesetterDisplay(pacesetterIdOpt);
 }
 
@@ -123,26 +122,34 @@
                                         std::shared_ptr<VsyncSchedule> vsyncSchedule) {
     demotePacesetterDisplay();
 
-    std::scoped_lock lock(mDisplayLock);
-    mRefreshRateSelectors.emplace_or_replace(displayId, std::move(selectorPtr));
-    mVsyncSchedules.emplace_or_replace(displayId, std::move(vsyncSchedule));
+    std::shared_ptr<VsyncSchedule> pacesetterVsyncSchedule;
+    {
+        std::scoped_lock lock(mDisplayLock);
+        mRefreshRateSelectors.emplace_or_replace(displayId, std::move(selectorPtr));
+        mVsyncSchedules.emplace_or_replace(displayId, std::move(vsyncSchedule));
 
-    promotePacesetterDisplay();
+        pacesetterVsyncSchedule = promotePacesetterDisplayLocked();
+    }
+    applyNewVsyncSchedule(std::move(pacesetterVsyncSchedule));
 }
 
 void Scheduler::unregisterDisplay(PhysicalDisplayId displayId) {
     demotePacesetterDisplay();
 
-    std::scoped_lock lock(mDisplayLock);
-    mRefreshRateSelectors.erase(displayId);
-    mVsyncSchedules.erase(displayId);
+    std::shared_ptr<VsyncSchedule> pacesetterVsyncSchedule;
+    {
+        std::scoped_lock lock(mDisplayLock);
+        mRefreshRateSelectors.erase(displayId);
+        mVsyncSchedules.erase(displayId);
 
-    // Do not allow removing the final display. Code in the scheduler expects
-    // there to be at least one display. (This may be relaxed in the future with
-    // headless virtual display.)
-    LOG_ALWAYS_FATAL_IF(mRefreshRateSelectors.empty(), "Cannot unregister all displays!");
+        // Do not allow removing the final display. Code in the scheduler expects
+        // there to be at least one display. (This may be relaxed in the future with
+        // headless virtual display.)
+        LOG_ALWAYS_FATAL_IF(mRefreshRateSelectors.empty(), "Cannot unregister all displays!");
 
-    promotePacesetterDisplay();
+        pacesetterVsyncSchedule = promotePacesetterDisplayLocked();
+    }
+    applyNewVsyncSchedule(std::move(pacesetterVsyncSchedule));
 }
 
 void Scheduler::run() {
@@ -679,6 +686,18 @@
 }
 
 void Scheduler::promotePacesetterDisplay(std::optional<PhysicalDisplayId> pacesetterIdOpt) {
+    std::shared_ptr<VsyncSchedule> pacesetterVsyncSchedule;
+
+    {
+        std::scoped_lock lock(mDisplayLock);
+        pacesetterVsyncSchedule = promotePacesetterDisplayLocked(pacesetterIdOpt);
+    }
+
+    applyNewVsyncSchedule(std::move(pacesetterVsyncSchedule));
+}
+
+std::shared_ptr<VsyncSchedule> Scheduler::promotePacesetterDisplayLocked(
+        std::optional<PhysicalDisplayId> pacesetterIdOpt) {
     // TODO(b/241286431): Choose the pacesetter display.
     mPacesetterDisplayId = pacesetterIdOpt.value_or(mRefreshRateSelectors.begin()->first);
     ALOGI("Display %s is the pacesetter", to_string(*mPacesetterDisplayId).c_str());
@@ -698,14 +717,22 @@
         vsyncSchedule->startPeriodTransition(mSchedulerCallback, refreshRate.getPeriod(),
                                              true /* force */);
     }
+    return vsyncSchedule;
+}
 
+void Scheduler::applyNewVsyncSchedule(std::shared_ptr<VsyncSchedule> vsyncSchedule) {
     onNewVsyncSchedule(vsyncSchedule->getDispatch());
+    std::vector<android::EventThread*> threads;
     {
         std::lock_guard<std::mutex> lock(mConnectionsLock);
+        threads.reserve(mConnections.size());
         for (auto& [_, connection] : mConnections) {
-            connection.thread->onNewVsyncSchedule(vsyncSchedule);
+            threads.push_back(connection.thread.get());
         }
     }
+    for (auto* thread : threads) {
+        thread->onNewVsyncSchedule(vsyncSchedule);
+    }
 }
 
 void Scheduler::demotePacesetterDisplay() {
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 74547d5..3423652 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -321,7 +321,18 @@
     // Chooses a pacesetter among the registered displays, unless `pacesetterIdOpt` is specified.
     // The new `mPacesetterDisplayId` is never `std::nullopt`.
     void promotePacesetterDisplay(std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+
+    // Changes to the displays (e.g. registering and unregistering) must be made
+    // while mDisplayLock is locked, and the new pacesetter then must be promoted while
+    // mDisplayLock is still locked. However, a new pacesetter means that
+    // MessageQueue and EventThread need to use the new pacesetter's
+    // VsyncSchedule, and this must happen while mDisplayLock is *not* locked,
+    // or else we may deadlock with EventThread.
+    std::shared_ptr<VsyncSchedule> promotePacesetterDisplayLocked(
+            std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
             REQUIRES(kMainThreadContext, mDisplayLock);
+    void applyNewVsyncSchedule(std::shared_ptr<VsyncSchedule>) EXCLUDES(mDisplayLock);
 
     // Blocks until the pacesetter's idle timer thread exits. `mDisplayLock` must not be locked by
     // the caller on the main thread to avoid deadlock, since the timer thread locks it before exit.