Re: [dpdk-dev] [PATCH v5 2/4] net/ixgbe: add support of reset

[Thomas Monjalon <thomas@monjalon.net>]

Hi,

30/06/2017 12:12, Wei Dai:
> +/*
> + * Reest PF device.
> + */
> +static int
> +ixgbe_dev_reset(struct rte_eth_dev *dev)
> +{
> +       int ret;
> +
> +       /* To avoid unexpected behavior in VF, disable PF reset */
> +       if (dev->data->sriov.active)
> +               return -ENOTSUP;
> +
> +       ret = eth_ixgbe_dev_uninit(dev);
> +       if (ret)
> +               return ret;
> +
> +       ret = eth_ixgbe_dev_init(dev);
> +
> +       return ret;
> +}

rte_eth_dev_reset() just do
+       rte_eth_dev_stop(port_id);
+       ret = dev->dev_ops->dev_reset(dev);

and dev_reset() just do
+       ret = eth_ixgbe_dev_uninit(dev);
+       ret = eth_ixgbe_dev_init(dev);

It is doing one more thing, the check of SR-IOV.
Unfortunately, this restriction is not documented.

This is the documentation of the new API:

 /**
+ * Reset a Ethernet device.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ */
+int rte_eth_dev_reset(uint8_t port_id);

It is really really too short.
>From the beginning of this proposal we are asking you to better explain
why this API is needed. It still does not appear in the doc.
Are you adding it to offer a new service to DPDK application developpers?
Or is it just a secret sauce that you will explain only to your customers?

This is what is expected to be documented:
- why/when this API must be used
- what the API will do
- what is needed to do after