commit 3ff44c7e852f5614514a15dcec78ba7857e5d010
author Dominik Laskowski <domlaskowski@google.com> Mon Jun 17 11:03:30 2024 -0400
committer Dominik Laskowski <domlaskowski@google.com> Mon Jun 17 16:15:49 2024 -0400
tree 5f8a5535e68dda6ff84510df09c6218866ad2388
parent 6312599b995865412436fb9033fbdf9efe99bd4f

SF: Fix pacesetter promotion for folded mirroring

The pacesetter display is demoted/promoted in response to a hotplug. On
foldables, the promoted display was hard-coded to the inner display, so
a hotplug while folded would incorrectly use that powered-off display as
the pacesetter, causing system-wide jank until the next fold/unfold.

Fixes: 347248313
Flag: EXEMPT bugfix
Test: Connect and disconnect external display while folded.
Test: Fold and unfold while external display is connected.
Test: Pacesetter is still correct on folded/unfolded boot.
Change-Id: Id5cb29c3cbaa8ed455a15d8be3a32e79a470cce5

services/surfaceflinger/Scheduler/Scheduler.h

diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index ccaa05f..1a4aa79 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -101,9 +101,16 @@
     using ConstVsyncSchedulePtr = std::shared_ptr<const VsyncSchedule>;
     using VsyncSchedulePtr = std::shared_ptr<VsyncSchedule>;
 
-    void registerDisplay(PhysicalDisplayId, RefreshRateSelectorPtr) REQUIRES(kMainThreadContext)
+    // After registration/unregistration, `activeDisplayId` is promoted to pacesetter. Note that the
+    // active display is never unregistered, since hotplug disconnect never happens for activatable
+    // displays, i.e. a foldable's internal displays or otherwise the (internal or external) primary
+    // display.
+    // TODO: b/255635821 - Remove active display parameters.
+    void registerDisplay(PhysicalDisplayId, RefreshRateSelectorPtr,
+                         PhysicalDisplayId activeDisplayId) REQUIRES(kMainThreadContext)
             EXCLUDES(mDisplayLock);
-    void unregisterDisplay(PhysicalDisplayId) REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+    void unregisterDisplay(PhysicalDisplayId, PhysicalDisplayId activeDisplayId)
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
 
     void run();
 
@@ -390,8 +397,9 @@
     // the caller on the main thread to avoid deadlock, since the timer thread locks it before exit.
     void demotePacesetterDisplay() REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock, mPolicyLock);
 
-    void registerDisplayInternal(PhysicalDisplayId, RefreshRateSelectorPtr, VsyncSchedulePtr)
-            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+    void registerDisplayInternal(PhysicalDisplayId, RefreshRateSelectorPtr, VsyncSchedulePtr,
+                                 PhysicalDisplayId activeDisplayId) REQUIRES(kMainThreadContext)
+            EXCLUDES(mDisplayLock);
 
     struct Policy;