RADEON_GRPH2_BUFFER_CNTL
grph2_cntl = RREG32(RADEON_GRPH2_BUFFER_CNTL);
WREG32(RADEON_GRPH2_BUFFER_CNTL, ((grph2_cntl & ~RADEON_GRPH_CRITICAL_POINT_MASK) |
(unsigned int)RREG32(RADEON_GRPH2_BUFFER_CNTL));