M1064_XPIXPLLCN
matroxfb_DAC_out(minfo, M1064_XPIXPLLCN, mnp >> 8);
matroxfb_DAC_in(minfo, M1064_XPIXPLLCN) != n ||
mnp |= matroxfb_DAC_in(minfo, M1064_XPIXPLLCN) << 8;