diff --git a/src/via_i2c.c b/src/via_i2c.c
index 7d75b29..aba3e4d 100644
--- a/src/via_i2c.c
+++ b/src/via_i2c.c
@@ -389,29 +389,21 @@ ViaI2CBus3Init(ScrnInfoPtr pScrn)
     pI2CBus->scrnIndex = pScrn->scrnIndex;
     pI2CBus->DriverPrivate.ptr = hwp;
 
-    switch (pVia->Chipset) {
-        case VIA_P4M800PRO:
-            DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO,
-                                "using alternative PutBits/GetBits functions for I2C Bus 3\n"));
-            pI2CBus->I2CPutBits = ViaI2C3SimplePutBits;
-            pI2CBus->I2CGetBits = ViaI2C3SimpleGetBits;
-            break;
-        default:
-            pI2CBus->I2CAddress = ViaI2C3Address;
+    pI2CBus->I2CAddress = ViaI2C3Address;
 #ifdef X_NEED_I2CSTART
-            pI2CBus->I2CStart = ViaI2C3Start;
+    pI2CBus->I2CStart = ViaI2C3Start;
 #endif
-            pI2CBus->I2CStop = ViaI2C3Stop;
-            pI2CBus->I2CPutByte = ViaI2C3PutByte;
-            pI2CBus->I2CGetByte = ViaI2C3GetByte;
-            pI2CBus->DriverPrivate.ptr = hwp;
-
-            pI2CBus->BitTimeout = 10;
-            pI2CBus->ByteTimeout = 10;
-            pI2CBus->HoldTime = 10;
-            pI2CBus->StartTimeout = 10;
-            break;
-    }
+    pI2CBus->I2CStop = ViaI2C3Stop;
+    pI2CBus->I2CPutByte = ViaI2C3PutByte;
+    pI2CBus->I2CGetByte = ViaI2C3GetByte;
+    pI2CBus->I2CPutBits = ViaI2C3SimplePutBits;
+    pI2CBus->I2CGetBits = ViaI2C3SimpleGetBits;
+    pI2CBus->DriverPrivate.ptr = hwp;
+
+    pI2CBus->BitTimeout = 10;
+    pI2CBus->ByteTimeout = 10;
+    pI2CBus->HoldTime = 10;
+    pI2CBus->StartTimeout = 10;
 
     if (!xf86I2CBusInit(pI2CBus)) {
         DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
diff --git a/src/via_ums.c b/src/via_ums.c
index 92b2cb5..8a152ca 100644
--- a/src/via_ums.c
+++ b/src/via_ums.c
@@ -82,6 +82,12 @@ viaMMIODisable(ScrnInfoPtr pScrn)
             break;
     }
 
+    /* Disable extended mode access. */
+    ViaSeqMask(hwp, 0x1A, 0x00, 0x08);
+
+    /* Lock extended I/O space. */
+    ViaSeqMask(hwp, 0x10, 0x00, 0x01);
+
     DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO,
                         "Exiting viaMMIODisable.\n"));
 }