RADEON_CRTC_VSYNC_DIS
uint32 mask = ~(RADEON_CRTC_DISPLAY_DIS | RADEON_CRTC_VSYNC_DIS | RADEON_CRTC_HSYNC_DIS);
(RADEON_CRTC_DISPLAY_DIS | RADEON_CRTC_VSYNC_DIS), mask );
(RADEON_CRTC_DISPLAY_DIS | RADEON_CRTC_VSYNC_DIS | RADEON_CRTC_HSYNC_DIS), mask );
if( (tmp & RADEON_CRTC_VSYNC_DIS) == 0 )
RADEON_CRTC_VSYNC_DIS |