[dpdk-dev] [PATCH v7 1/4] ethdev: add apis to support access device info

[Stephen Hemminger]

On Wed, 17 Jun 2015 18:22:12 -0400
Liang-Min Larry Wang <liang-min.wang at intel.com> wrote:

> +int
> +rte_eth_dev_reg_length(uint8_t port_id)
> +{
> +	struct rte_eth_dev *dev;
> +
> +	if ((dev= &rte_eth_devices[port_id]) == NULL) {
> +		PMD_DEBUG_TRACE("Invalid port device\n");
> +		return -ENODEV;
> +	}

Some minor nits:
  * for consistency you should add valid port check here.
  * style:
    - don't do assignment in if() unless it really helps readability
    - need whitespace

	if (!rte_eth_dev_is_valid_port(portid)) {
		PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id);
		return -ENODEV;
	}

	dev = &rte_eth_devices[port_id];
	if (dev == NULL) {
		PMD_DEBUG("Invalid port device\n");
		return -ENODEV:
	}
...

This code pattern is so common it really should be a function.

	dev = rte_eth_dev_get(port_id);
	if (dev == NULL) {
		PMD_DEBUG("Invalid port device\n");
		return -ENODEV;
	}

And then add a macro to generate this??