From 03543eeab4627483100c360805bf7885c86c3b60 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Fri, 29 May 2015 22:51:34 -0700
Subject: [PATCH] GBA SIO: Fix regression when switching modes

---
 src/gba/sio.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/gba/sio.c b/src/gba/sio.c
index 16d9772df..49f66ff58 100644
--- a/src/gba/sio.c
+++ b/src/gba/sio.c
@@ -131,6 +131,10 @@ void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value) {
 }
 
 void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
+	if ((value ^ sio->siocnt) & 0x3000) {
+		sio->siocnt = value & 0x3000;
+		_switchMode(sio);
+	}
 	if (sio->activeDriver && sio->activeDriver->writeRegister) {
 		value = sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOCNT, value);
 	} else {
@@ -151,7 +155,6 @@ void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
 		}
 	}
 	sio->siocnt = value;
-	_switchMode(sio);
 }
 
 void GBASIOWriteSIOMLT_SEND(struct GBASIO* sio, uint16_t value) {