Re: [PATCH] net/netvsc: use rte_eth_dev_set_mtu to set VF MTU

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 7/19/2024 10:20 PM, Stephen Hemminger wrote:
> On Fri, 19 Jul 2024 21:39:04 +0100
> Ferruh Yigit <ferruh.yigit@amd.com> wrote:
> 
>>> --- a/drivers/net/netvsc/hn_vf.c
>>> +++ b/drivers/net/netvsc/hn_vf.c
>>> @@ -264,7 +264,7 @@ int hn_vf_add(struct rte_eth_dev *dev, struct hn_data *hv)
>>>  			goto exit;
>>>  		}
>>>  
>>> -		ret = hn_vf_mtu_set(dev, dev->data->mtu);
>>> +		ret = rte_eth_dev_set_mtu(port, dev->data->mtu);
>>>  
>>
>> As 'rte_eth_dev_set_mtu()' calls 'hn_vf_mtu_set()' in the call chain,
>> won't it cause same problem?
> 
> The port is the vf so it will call the set_mtu on the VF not the netvsc
> device so it is not in the call chain.
> 

ack

>>
>> Does it help to make unlocked version of 'hn_vf_mtu_set()':
>> ```
>> _hn_vf_mtu_set()
>> 	// set mtu without lock
>>
>> hn_vf_mtu_set()
>> 	lock()
>> 	_hn_vf_mtu_set()
>> 	unlock()
>> ```
> 
> That was original proposal, but using rte_eth_dev_set_mtu() on the VF
> port has more error checking.