vd_to_axi_desc
axi_chan_list_dump_lli(chan, vd_to_axi_desc(vd));
desc = vd_to_axi_desc(vd);
axi_desc_put(vd_to_axi_desc(vdesc));
length = vd_to_axi_desc(vdesc)->length;
completed_blocks = vd_to_axi_desc(vdesc)->completed_blocks;
len = vd_to_axi_desc(vdesc)->hw_desc[0].len;
desc = vd_to_axi_desc(vd);