Re: [PATCH net-next 5/7] Driver: Vmxnet3: Add support for get_coalesce, set_coalesce ethtool operations

[David Miller]

From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Date: Sat, 07 May 2016 13:04:46 +0100

> On Fri, 2016-05-06 at 16:12 -0700, Shrikrishna Khare wrote:
> [...]
>> +static int
>> +vmxnet3_set_coalesce(struct net_device *netdev, struct ethtool_coalesce *ec)
>> +{
> [...]
>> +	switch (ec->rx_coalesce_usecs) {
>> +	case VMXNET3_COALESCE_DEFAULT:
>> +	case VMXNET3_COALESCE_DISABLED:
>> +	case VMXNET3_COALESCE_ADAPT:
>> +		if (ec->tx_max_coalesced_frames ||
>> +		    ec->tx_max_coalesced_frames_irq ||
>> +		    ec->rx_max_coalesced_frames_irq) {
>> +			return -EINVAL;
>> +		}
>> +		memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
>> +		adapter->coal_conf->coalMode = ec->rx_coalesce_usecs;
>> +		break;
>> +	case VMXNET3_COALESCE_STATIC:
> [...]
> 
> I don't want to see drivers introducing magic values for fields that
> are denominated in microseconds (especially not for 0, which is the
> correct way to specify 'no coalescing').  If the current
> ethtool_coalesce structure is inadequate, propose an extension.

Agreed.