Re: [v2] ethernet: ti: eliminate a bit of duplicate code in gbe_probe()

From: Markus Elfring
Date: Wed Apr 10 2019 - 05:47:25 EST


>>> @@ -3651,22 +3651,18 @@ static int gbe_probe(struct netcp_device *netcp_device, struct device *dev,
>>> if (ret)
>>> return ret;
>>>
>>> - interfaces = of_get_child_by_name(node, "interfaces");
>>> - if (!interfaces)
>>> - dev_err(dev, "could not find interfaces\n");
>>> -
>>
>> How do you think about to skip a bit of statements as a reaction for
>> such a null pointer?
>> https://elixir.bootlin.com/linux/v5.1-rc4/source/drivers/net/ethernet/ti/netcp_ethss.c#L3562
â
> Maybe you need to look at the implementation of for_each_child_of_node() and of_node_put().
> NULL check before those functions is not needed.

This information is reasonable in principle.

Was the reference counter incremented even if a null pointer was returned
by such a function call?


>>> ret = netcp_txpipe_init(&gbe_dev->tx_pipe, netcp_device,
>>> gbe_dev->dma_chan_name, gbe_dev->tx_queue_id);
>>> - if (ret) {
>>> - of_node_put(interfaces);
>>> + if (ret)
>>> return ret;
>>> - }
>>>
>>> ret = netcp_txpipe_open(&gbe_dev->tx_pipe);
>>> - if (ret) {
>>> - of_node_put(interfaces);
>>> + if (ret)
>>> return ret;
>>> - }

Does the preparation of the NetCP pipe still matter in this special use case?


>>> +
>>> + interfaces = of_get_child_by_name(node, "interfaces");
>>> + if (!interfaces)
>>> + dev_err(dev, "could not find interfaces\n");
>>>
>>> /* Create network interfaces */
>>> INIT_LIST_HEAD(&gbe_dev->gbe_intf_head);
>>
>> Can code like the following trigger corresponding software development concerns?
>>
>> for_each_child_of_node(interfaces, interface) {
>> â
>> }
>> of_node_put(interfaces);
>>
â
>> if (!gbe_dev->num_slaves)
>> dev_warn(dev, "No network interface configured\n");

Is this message really required as another response then?

Regards,
Markus