NV_CIO_CRE_21
uint8_t saved_cr21 = nv04_display(dev)->saved_reg.crtc_reg[head].CRTC[NV_CIO_CRE_21];
rd_cio_state(dev, head, regp, NV_CIO_CRE_21);
cr21 = NVReadVgaCrtc(dev, head, NV_CIO_CRE_21) | 0xfa;
NVWriteVgaCrtc(dev, head, NV_CIO_CRE_21, cr21);