sync_for_cpu
sync_for_cpu(msm_obj);
u32 sync_for_cpu;
meta->sync_for_cpu = 0;
meta->sync_for_cpu = meta->offset + meta->headroom + len;
if (meta->sync_for_cpu <= meta->offset + rx->headroom)
len = meta->sync_for_cpu - meta->offset - rx->headroom;
meta->sync_for_cpu = 0;