Francois Romieu [mailto:romieu@xxxxxxxxxxxxx] > Sent: Thursday, August 15, 2013 8:26 PM > To: Hayeswang > Cc: netdev@xxxxxxxxxxxxxxx; nic_swsd; > linux-kernel@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; David Miller > Subject: Re: [PATCH net-next v2 1/3] net/usb/r8152: support > aggregation > [...] > > +static > > +int r8152_submit_rx(struct r8152 *tp, struct rx_agg *agg, > gfp_t mem_flags); > > + > > It's a new, less than 10 lines function without driver > internal dependencies. > > The forward declaration is not needed. The r8152_submit_rx() need the declaration of read_bulk_callback(), and the read_bulk_callback() need the declaration of r8152_submit_rx(), too. It likes a dead lock, so I have no idea how to do it without another declaration. [...] > > - if (!netif_device_present(netdev)) > > + if (!netif_carrier_ok(netdev)) > > return; > > How is it related to the subject of the patch ? When link down, the driver would cancel all bulks. This avoid the re-submitting bulk. > [...] > > +static void rx_bottom(struct r8152 *tp) > > +{ > > + struct net_device_stats *stats; > > + struct net_device *netdev; > > + struct rx_agg *agg; > > + struct rx_desc *rx_desc; > > + unsigned long lockflags; > > Idiom: 'flags'. > > > + struct list_head *cursor, *next; > > + struct sk_buff *skb; > > + struct urb *urb; > > + unsigned pkt_len; > > + int len_used; > > + u8 *rx_data; > > + int ret; > > The scope of these variables is needlessly wide. > > > + > > + netdev = tp->netdev; > > + > > + stats = rtl8152_get_stats(netdev); > > + > > + spin_lock_irqsave(&tp->rx_lock, lockflags); > > + list_for_each_safe(cursor, next, &tp->rx_done) { > > + list_del_init(cursor); > > + spin_unlock_irqrestore(&tp->rx_lock, lockflags); > > + > > + agg = list_entry(cursor, struct rx_agg, list); > > + urb = agg->urb; > > + if (urb->actual_length < ETH_ZLEN) { > > goto submit; > > > + ret = r8152_submit_rx(tp, agg, GFP_ATOMIC); > > + spin_lock_irqsave(&tp->rx_lock, lockflags); > > + if (ret && ret != -ENODEV) { > > + list_add_tail(&agg->list, next); > > + tasklet_schedule(&tp->tl); > > + } > > + continue; > > + } > > (remove the line above) > > [...] > > + rx_data = rx_agg_align(rx_data + pkt_len + 4); > > + rx_desc = (struct rx_desc *)rx_data; > > + pkt_len = le32_to_cpu(rx_desc->opts1) & > RX_LEN_MASK; > > + len_used = (int)(rx_data - (u8 *)agg->head); > > + len_used += sizeof(struct rx_desc) + pkt_len; > > + } > > + > > submit: > > > + ret = r8152_submit_rx(tp, agg, GFP_ATOMIC); > > + spin_lock_irqsave(&tp->rx_lock, lockflags); > > + if (ret && ret != -ENODEV) { > > + list_add_tail(&agg->list, next); > > + tasklet_schedule(&tp->tl); > > + } > > + } > > + spin_unlock_irqrestore(&tp->rx_lock, lockflags); > > +} > > It should be possible to retrieve more items in the spinlocked section > so as to have a chance to batch more work. I have not thought > too deeply > about it. I only lock when I want to remove or inser the agg list, and unlock as soon as possible. I don't think I keep locking for a long time. Best Regards, Hayes -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
