On Tuesday 25 March 2014 12:06:31 Zhangfei Gao wrote: > Dear Arnd > > On Mon, Mar 24, 2014 at 11:18 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Monday 24 March 2014 22:14:56 Zhangfei Gao wrote: > > > >> + > >> +static void hip04_tx_reclaim(struct net_device *ndev, bool force) > >> +{ > >> + struct hip04_priv *priv = netdev_priv(ndev); > >> + unsigned tx_head = priv->tx_head; > >> + unsigned tx_tail = priv->tx_tail; > >> + struct tx_desc *desc = &priv->tx_desc[priv->tx_tail]; > >> + > >> + while (tx_tail != tx_head) { > >> + if (desc->send_addr != 0) { > >> + if (force) > >> + desc->send_addr = 0; > >> + else > >> + break; > >> + } > >> + if (priv->tx_phys[tx_tail]) { > >> + dma_unmap_single(&ndev->dev, priv->tx_phys[tx_tail], > >> + priv->tx_skb[tx_tail]->len, DMA_TO_DEVICE); > >> + priv->tx_phys[tx_tail] = 0; > >> + } > >> + dev_kfree_skb_irq(priv->tx_skb[tx_tail]); > >> + priv->tx_skb[tx_tail] = NULL; > >> + tx_tail = TX_NEXT(tx_tail); > >> + priv->tx_count--; > >> + } > >> + priv->tx_tail = tx_tail; > >> +} > > > > I think you still need to find a solution to ensure that the tx reclaim is > > called eventually through a method other than start_xmit. > > In the iperf stress test, if move reclaim to poll, there is some > error, sometimes sending zero packets. > While keep reclaim in the xmit to reclaim transmitted packets looks > stable in the test, > There TX_DESC_NUM desc can be used. What I meant is that you need a correct implementation, presumably you added a bug when you moved the function to poll(), and also you forgot to add a timer. > >> + priv->map = syscon_regmap_lookup_by_compatible("hisilicon,hip04-ppe"); > >> + if (IS_ERR(priv->map)) { > >> + dev_warn(d, "no hisilicon,hip04-ppe\n"); > >> + ret = PTR_ERR(priv->map); > >> + goto init_fail; > >> + } > >> + > >> + n = of_parse_phandle(node, "port-handle", 0); > >> + if (n) { > >> + ret = of_property_read_u32(n, "reg", &priv->port); > >> + if (ret) { > >> + dev_warn(d, "no reg info\n"); > >> + goto init_fail; > >> + } > >> + > >> + ret = of_property_read_u32(n, "channel", &priv->chan); > >> + if (ret) { > >> + dev_warn(d, "no channel info\n"); > >> + goto init_fail; > >> + } > >> + } else { > >> + dev_warn(d, "no port-handle\n"); > >> + ret = -EINVAL; > >> + goto init_fail; > >> + } > > > > Doing the lookup by "compatible" string doesn't really help you > > at solve the problem of single-instance ppe at all, because that > > function will only ever look at the first one. Use > > syscon_regmap_lookup_by_phandle instead and pass the phandle > > you get from the "port-handle" property. > > Did some experiment, the only ppe base is got from syscon probe. > And looking up by "compatible" did work for three controllers at the same time. The point is that it won't work for more than one ppe instance. > > Also, since you decided to treat the ppe as a dump regmap, I would > > recommend moving the 'reg' and 'channel' properties into arguments > > of the port-handle link, and retting rid of the child nodes of > > the ppe, like: > > > > + ppe: ppe@28c0000 { > > + compatible = "hisilicon,hip04-ppe", "syscon"; > > + reg = <0x28c0000 0x10000>; > > + }; > > + > > + fe: ethernet@28b0000 { > > + compatible = "hisilicon,hip04-mac"; > > + reg = <0x28b0000 0x10000>; > > + interrupts = <0 413 4>; > > + phy-mode = "mii"; > > + port-handle = <&ppe 0xf1 0>; > > + }; > > > > Would you mind giving more hints about how to parse the args. > I am thinking of using of_parse_phandle_with_args, is that correct method? I would just use of_property_read_u32_array() to read all three cells, then pass the first cell entry into syscon_regmap_lookup_by_phandle. of_parse_phandle_with_args() is what you would use if you were registering a higher-level driver for the ppe rather than using syscon. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html