Re: [PATCH v2 4/4] net: ethoc: implement ethtool operations

[Ben Hutchings]

On Wed, 2014-01-29 at 10:00 +0400, Max Filippov wrote:
> The following methods are implemented:
> - get/set settings;
> - get registers length/registers;
> - get link state (standard implementation);
> - get/set ring parameters;
> - get timestamping info (standard implementation).
[...]
> --- a/drivers/net/ethernet/ethoc.c
> +++ b/drivers/net/ethernet/ethoc.c
> [...]
> +static int ethoc_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
> +{
> +	struct ethoc *priv = netdev_priv(dev);
> +	struct phy_device *phydev = priv->phy;
> +
> +	if (!phydev)
> +		return -ENODEV;
> +
> +	return phy_ethtool_gset(phydev, cmd);
> +}
> +
> +static int ethoc_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
> +{
> +	struct ethoc *priv = netdev_priv(dev);
> +	struct phy_device *phydev = priv->phy;
> +
> +	if (!phydev)
> +		return -ENODEV;
> +
> +	return phy_ethtool_sset(phydev, cmd);
> +}

I think these should return -EOPNOTSUPP in the PHY-less case, just as if
the set_settings pointer was not set.

[...]
> +static void ethoc_get_ringparam(struct net_device *dev,
> +				struct ethtool_ringparam *ring)
> +{
> +	struct ethoc *priv = netdev_priv(dev);
> +
> +	ring->rx_max_pending = priv->num_bd;
> +	ring->rx_mini_max_pending = 0;
> +	ring->rx_jumbo_max_pending = 0;
> +	ring->tx_max_pending = priv->num_bd;
> +
> +	ring->rx_pending = priv->num_rx;
> +	ring->rx_mini_pending = 0;
> +	ring->rx_jumbo_pending = 0;
> +	ring->tx_pending = priv->num_tx;
> +}
> +
> +static int ethoc_set_ringparam(struct net_device *dev,
> +			       struct ethtool_ringparam *ring)
> +{
> +	struct ethoc *priv = netdev_priv(dev);
> +
> +	if (netif_running(dev))
> +		return -EBUSY;

This is unhelpful.  Most implementations of this operation will restart
the interface if it's running.

> +	priv->num_tx = rounddown_pow_of_two(ring->tx_pending);

Range check?

> +	priv->num_rx = priv->num_bd - priv->num_tx;
> +	if (priv->num_rx > ring->rx_pending)
> +		priv->num_rx = ring->rx_pending;

So the RX ring may only ever be shrunk?!  Did you mean to compare with
priv->num_bd instead?

> +	return 0;
> +}
> +
> +const struct ethtool_ops ethoc_ethtool_ops = {

static

> +	.get_settings = ethoc_get_settings,
> +	.set_settings = ethoc_set_settings,
> +	.get_regs_len = ethoc_get_regs_len,
> +	.get_regs = ethoc_get_regs,
> +	.get_link = ethtool_op_get_link,
> +	.get_ringparam = ethoc_get_ringparam,
> +	.set_ringparam = ethoc_set_ringparam,
> +	.get_ts_info = ethtool_op_get_ts_info,
> +};
[...]

-- 
Ben Hutchings
It is a miracle that curiosity survives formal education. - Albert Einstein

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