radeon_pm_debug_check_in_vbl
radeon_pm_debug_check_in_vbl(rdev, false);
radeon_pm_debug_check_in_vbl(rdev, true);
radeon_pm_debug_check_in_vbl(rdev, false);
radeon_pm_debug_check_in_vbl(rdev, true);
static bool radeon_pm_debug_check_in_vbl(struct radeon_device *rdev, bool finish);