CAM_IOSCHED_FLAG_CALLOUT_ACTIVE
isc->flags |= CAM_IOSCHED_FLAG_CALLOUT_ACTIVE;
if (isc->flags & CAM_IOSCHED_FLAG_CALLOUT_ACTIVE) {
isc->flags &= ~ CAM_IOSCHED_FLAG_CALLOUT_ACTIVE;
isc->flags |= CAM_IOSCHED_FLAG_CALLOUT_ACTIVE;