viafb_vx855_dma_descr
struct viafb_vx855_dma_descr *descr;
nsg*sizeof(struct viafb_vx855_dma_descr),
nextdesc = descr_handle + sizeof(struct viafb_vx855_dma_descr);
nextdesc += sizeof(struct viafb_vx855_dma_descr);
nsg*sizeof(struct viafb_vx855_dma_descr), descrpages,