/* Output : di -> Tap4 Reg. Setting Pointer */
 /* Description : */
 /* --------------------------------------------------------------------- */
-static struct XGI301C_Tap4TimingStruct *XGI_GetTap4Ptr(unsigned short tempcx,
-               struct vb_device_info *pVBInfo)
+static struct XGI301C_Tap4TimingStruct const
+*XGI_GetTap4Ptr(unsigned short tempcx, struct vb_device_info *pVBInfo)
 {
        unsigned short tempax, tempbx, i;
-
-       struct XGI301C_Tap4TimingStruct *Tap4TimingPtr;
+       struct XGI301C_Tap4TimingStruct const *Tap4TimingPtr;
 
        if (tempcx == 0) {
                tempax = pVBInfo->VGAHDE;
 static void XGI_SetTap4Regs(struct vb_device_info *pVBInfo)
 {
        unsigned short i, j;
-
-       struct XGI301C_Tap4TimingStruct *Tap4TimingPtr;
+       struct XGI301C_Tap4TimingStruct const *Tap4TimingPtr;
 
        if (!(pVBInfo->VBType & VB_XGI301C))
                return;
 
        0x58, 0xe4, 0x73, 0xd0, 0x13
 };
 
-static struct XGI301C_Tap4TimingStruct xgifb_tap4_timing[] = {
+static const struct XGI301C_Tap4TimingStruct xgifb_tap4_timing[] = {
        {0, {
        0x00, 0x20, 0x00, 0x00, 0x7F, 0x20, 0x02, 0x7F, /* ; C0-C7 */
        0x7D, 0x20, 0x04, 0x7F, 0x7D, 0x1F, 0x06, 0x7E, /* ; C8-CF */
        }
 };
 
-static struct XGI301C_Tap4TimingStruct PALTap4Timing[] = {
+static const struct XGI301C_Tap4TimingStruct PALTap4Timing[] = {
        {600,   {
                0x05, 0x19, 0x05, 0x7D, 0x03, 0x19, 0x06, 0x7E, /* ; C0-C7 */
                0x02, 0x19, 0x08, 0x7D, 0x01, 0x18, 0x0A, 0x7D, /* ; C8-CF */
        }
 };
 
-static struct XGI301C_Tap4TimingStruct xgifb_ntsc_525_tap4_timing[] = {
+static const struct XGI301C_Tap4TimingStruct xgifb_ntsc_525_tap4_timing[] = {
        {480,   {
                0x04, 0x1A, 0x04, 0x7E, 0x03, 0x1A, 0x06, 0x7D, /* ; C0-C7 */
                0x01, 0x1A, 0x08, 0x7D, 0x00, 0x19, 0x0A, 0x7D, /* ; C8-CF */
        }
 };
 
-static struct XGI301C_Tap4TimingStruct YPbPr750pTap4Timing[] = {
+static const struct XGI301C_Tap4TimingStruct YPbPr750pTap4Timing[] = {
        {0xFFFF, {
                 0x05, 0x19, 0x05, 0x7D, 0x03, 0x19, 0x06, 0x7E, /* ; C0-C7 */
                 0x02, 0x19, 0x08, 0x7D, 0x01, 0x18, 0x0A, 0x7D, /* ; C8-CF */