Re: [dpdk-dev] [PATCH 2/2] kni: set default carrier state to 'off'

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

On 9/12/2018 12:29 AM, Dan Gora wrote:
> Set the carrier state to 'off' when the interface is instantiated
> or when it is marked 'up' or 'down'.  This is necessary to set the
> interface to a known operational state until the carrier state is
> changed with rte_kni_update_link().

Why setting to no-carrier mode by default? This will change the behavior of
interfaces and may effect others. And indeed I didn't get why this is required?

> 
> Signed-off-by: Dan Gora <dg@adax.com>
> ---
>  kernel/linux/kni/kni_misc.c | 2 ++
>  kernel/linux/kni/kni_net.c  | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
> index fa69f8e63..45649499d 100644
> --- a/kernel/linux/kni/kni_misc.c
> +++ b/kernel/linux/kni/kni_misc.c
> @@ -466,6 +466,8 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
>  		return -ENODEV;
>  	}
>  
> +	netif_carrier_off(net_dev);
> +
>  	ret = kni_run_thread(knet, kni, dev_info.force_bind);
>  	if (ret != 0)
>  		return ret;
> diff --git a/kernel/linux/kni/kni_net.c b/kernel/linux/kni/kni_net.c
> index 7fcfa106c..1f8ba0700 100644
> --- a/kernel/linux/kni/kni_net.c
> +++ b/kernel/linux/kni/kni_net.c
> @@ -133,6 +133,7 @@ kni_net_open(struct net_device *dev)
>  	struct kni_dev *kni = netdev_priv(dev);
>  
>  	netif_start_queue(dev);
> +	netif_carrier_off(dev);
>  
>  	memset(&req, 0, sizeof(req));
>  	req.req_id = RTE_KNI_REQ_CFG_NETWORK_IF;
> @@ -152,6 +153,7 @@ kni_net_release(struct net_device *dev)
>  	struct kni_dev *kni = netdev_priv(dev);
>  
>  	netif_stop_queue(dev); /* can't transmit any more */
> +	netif_carrier_off(dev);
>  
>  	memset(&req, 0, sizeof(req));
>  	req.req_id = RTE_KNI_REQ_CFG_NETWORK_IF;
>