Messages in this thread | | | Date | Thu, 14 May 2009 09:55:52 +0200 | From | Wolfgang Grandegger <> | Subject | Re: [PATCH v2 3/7] [PATCH 3/8] can: CAN Network device driver and Netlink interface |
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Jonathan Corbet wrote: > [Quick review ...] > >> +/* >> + * CAN device restart for bus-off recovery >> + */ >> +int can_restart_now(struct net_device *dev) >> +{ >> + struct can_priv *priv = netdev_priv(dev); >> + struct net_device_stats *stats = &dev->stats; >> + struct sk_buff *skb; >> + struct can_frame *cf; >> + int err; >> + >> + /* Synchronize with dev->hard_start_xmit() */ >> + netif_tx_lock(dev); >> + >> + /* Ensure that no more messages can go out */ >> + if (netif_carrier_ok(dev)) >> + netif_carrier_off(dev); >> + >> + /* Ensure that no more messages can come in */ >> + err = priv->do_set_mode(dev, CAN_MODE_STOP); >> + if (err) >> + return err; > > This leaves _xmit_lock held and carrier off. Is that really what you want > to do? > >> + >> + /* Now it's save to clean up */ >> + del_timer_sync(&priv->restart_timer); >> + can_flush_echo_skb(dev); >> + >> + dev_dbg(dev->dev.parent, "restarted\n"); >> + priv->can_stats.restarts++; >> + >> + /* send restart message upstream */ >> + skb = dev_alloc_skb(sizeof(struct can_frame)); >> + if (skb == NULL) >> + return -ENOMEM; > > ...here too... > >> + skb->dev = dev; >> + skb->protocol = htons(ETH_P_CAN); >> + cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); >> + memset(cf, 0, sizeof(struct can_frame)); >> + cf->can_id = CAN_ERR_FLAG | CAN_ERR_RESTARTED; >> + cf->can_dlc = CAN_ERR_DLC; >> + >> + netif_rx(skb); >> + >> + dev->last_rx = jiffies; >> + stats->rx_packets++; >> + stats->rx_bytes += cf->can_dlc; >> + >> + /* Now restart the device */ >> + err = priv->do_set_mode(dev, CAN_MODE_START); >> + if (err) >> + return err; > > ...and here too. Do you maybe want to get rid of the middle-of-function > returns and switch to the "goto out" convention?
Right, needs to be fixed.
>> + netif_carrier_on(dev); >> + >> + netif_tx_unlock(dev); >> + >> + return 0; >> +} >> + >> +static void can_restart_after(unsigned long data) >> +{ >> + struct net_device *dev = (struct net_device *)data; >> + >> + can_restart_now(dev); >> +} > > can_restart_after what? I find myself confused by this function and > wondering why it exists.
It's just a wrapper to make the compile happy. It's the timer callback function used here:
priv->restart_timer.function = can_restart_after;
in contrast to can_restart_now(), which can be called via netlink interface as well. Would the name "can_restart_callback" be more appropriate?
Wolfgang.
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