> From: saeed bishara [mailto:[EMAIL PROTECTED] > Hi Dan, > I think you have a bug in this function, the list_splice_init adds the > new slots in the head of the chain_node, but you get the > old_chain_tail (latest descriptor) from the tail of the chain!! > > > +static dma_cookie_t > > +iop_adma_tx_submit(struct dma_async_tx_descriptor *tx) > > +{ > > + > > + old_chain_tail = list_entry(iop_chan->chain.prev, > > + struct iop_adma_desc_slot, chain_node); > > + list_splice_init(&sw_desc->group_list, &old_chain_tail- > >chain_node); > > + > > + /* fix up the hardware chain */ > > + iop_desc_set_next_desc(old_chain_tail, grp_start->phys); > > + [ dropped akpm, davem, jeff, and chris from the cc ]
This looks ok to me. &sw_desc->group_list is the head of a new list of descriptors to be added to the chain. old_chain_tail is youngest descriptor at the end of the current channel chain. Before list_splice_init: old_chain_tail->next = channel_chain_head channel_chain_head->prev = old_chain_tail new_chain_start->prev = sw_desc->group_list; new_chain_end->next = sw_desc->group_list; After list_splice_init: new_chain_start->prev = old_chain_tail old_chain_tail->next = new_chain_start new_chain_end->next = channel_chain_head channel_chain_head->prev = new_chain_end sw_desc->group_list is empty -- Dan - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
