RADEON_BIOS_4_SCRATCH
values->bios_4_scratch = INREG( regs, RADEON_BIOS_4_SCRATCH );
OUTREG( regs, RADEON_BIOS_4_SCRATCH, values->bios_4_scratch);
if (si->is_mobility && (INREG(ai->regs, RADEON_BIOS_4_SCRATCH) & 4)) {