ATI Radeon KMS vs. UMS With Ubuntu 10.04

[agd5f]

Both can be involved. Setting vblank_mode=0 will disable the frame synchronization stuff and commenting out this line:
info->accel_state->vsync = TRUE;
in radeon_dri2.c in the ddx will disable the vline waits to avoid tearing on gl buffer swaps. The variable name, vsync, in this case is misleading, it should really be called vline_wait.

[xeros]

Both can be involved. Setting vblank_mode=0 will disable the frame synchronization stuff and commenting out this line:
info->accel_state->vsync = TRUE;
in radeon_dri2.c in the ddx will disable the vline waits to avoid tearing on gl buffer swaps. The variable name, vsync, in this case is misleading, it should really be called vline_wait.

I have tried to vblank_mode=0 and this alone works for glxgears but not Nexuiz. I have tried to switch off vsync in driconf, but it didn't help either.
Could you make "info->accel_state->vsync = TRUE;" switchable option for kernel/dri/etc.? I don't want to get rid of it completely as it might really help for video but it's a problem with games.