Subject: Re: [PATCH] net-sysfs: allow changing sysfs carrier when interface is down

From: Jakub Kicinski <[email-masked]>
Date: Wed, 1 Jun 2022 18:01:47 -0700

On Thu, 2 Jun 2022 02:35:23 +0200 Joakim Tjernlund wrote:
> UP/DOWN and carrier are async events and it makes sense one can
> adjust carrier in sysfs before bringing the interface up.

Can you explain your use case?

> Signed-off-by: Joakim Tjernlund <[email-masked]>
> Cc: [email-masked]

Seems a little too risky of a change to push into stable.

> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index a4ae65263384..3418ef7ef2d8 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -167,8 +167,6 @@ static DEVICE_ATTR_RO(broadcast);
>  
>  static int change_carrier(struct net_device *dev, unsigned long new_carrier)
>  {
> -	if (!netif_running(dev))
> -		return -EINVAL;
>  	return dev_change_carrier(dev, (bool)new_carrier);
>  }