spin_lock_bh(&iop_chan->lock);
slot_cnt = iop_chan_zero_sum_slot_count(len, src_cnt, &slots_per_op);
sw_desc = iop_adma_alloc_slots(iop_chan, slot_cnt, slots_per_op);
if (sw_desc) {
grp_start = sw_desc->group_head;
spin_lock_bh(&iop_chan->lock);
slot_cnt = iop_chan_zero_sum_slot_count(len, src_cnt, &slots_per_op);
sw_desc = iop_adma_alloc_slots(iop_chan, slot_cnt, slots_per_op);
if (sw_desc) {
grp_start = sw_desc->group_head;