RADEON_DAC_CNTL
dac_cntl = RREG32(RADEON_DAC_CNTL);
WREG32(RADEON_DAC_CNTL, dac_cntl);
uint32_t dac_cntl = RREG32(RADEON_DAC_CNTL);
WREG32(RADEON_DAC_CNTL, dac_cntl);
WREG32_P(RADEON_DAC_CNTL,
dac_cntl = RREG32(RADEON_DAC_CNTL);
WREG32(RADEON_DAC_CNTL, tmp);
if (RREG32(RADEON_DAC_CNTL) & RADEON_DAC_CMP_OUTPUT)
WREG32(RADEON_DAC_CNTL, dac_cntl);