M CHANGES → CHANGES

@@ -50,6 +50,7 @@ - GBA Serialize: Fix alignment check when loading states
  - GBA SIO: Fix copying Normal mode transfer values
  - GBA SIO: Fix Normal mode being totally broken (fixes mgba.io/i/1800)
  - GBA SIO: Fix deseralizing SIO registers
+ - GBA SIO: Fix hanging on starting a second multiplayer window (fixes mgba.io/i/854)
  - GBA Video: Latch scanline at end of Hblank (fixes mgba.io/i/1319)
  - GBA Video: Fix Hblank timing
  - GBA Video: Implement green swap (fixes mgba.io/i/1609)

M src/gba/sio/lockstep.c → src/gba/sio/lockstep.c

@@ -444,6 +444,7 @@ static void _GBASIOLockstepNodeProcessEvents(struct mTiming* timing, void* user, uint32_t cyclesLate) {
 	struct GBASIOLockstepNode* node = user;
 	mLockstepLock(&node->p->d);
 	if (node->p->d.attached < 2) {
+		mTimingSchedule(timing, &node->event, GBASIOCyclesPerTransfer[GBASIOMultiplayerGetBaud(node->d.p->siocnt)][0]);
 		mLockstepUnlock(&node->p->d);
 		return;
 	}