RADEON_OV0_REG_LOAD_CNTL
OUTREG( regs, RADEON_OV0_REG_LOAD_CNTL, 0 );
OUTREG( regs, RADEON_OV0_REG_LOAD_CNTL, RADEON_REG_LD_CTL_LOCK );
while( (INREG( regs, RADEON_OV0_REG_LOAD_CNTL)
OUTREG( regs, RADEON_OV0_REG_LOAD_CNTL, 0 );