Hi Tim,

> +bool wiphy_is_scan_ie_supported(struct wiphy *wiphy)
> +{
> +	return wiphy->max_scan_ie_len ? true : false;
> +}
> +

Lets not go overboard adding APIs to wiphy.c now..  You already have 
something that can accomplish the job, so just use that.

<snip>

> diff --git a/src/wsc.c b/src/wsc.c
> index bac6e0cc..ed211834 100644
> --- a/src/wsc.c
> +++ b/src/wsc.c
> @@ -1108,6 +1108,13 @@ static void wsc_add_interface(struct netdev *netdev)
>   	struct l_dbus *dbus = dbus_get_bus();
>   	struct wsc *wsc;
>   
> +	if (!wiphy_is_scan_ie_supported(netdev_get_wiphy(netdev))) {
> +		l_info("Simple Configuration isn't supported by ifindex %u",
> +						netdev_get_ifindex(netdev));
> +
> +		return;
> +	}

I don't like the l_info here.  This will get printed way too many times 
due to ifup/ifdown.  Perhaps we need to add an L_WARN_ONCE or do this 
statically here.

> +
>   	wsc = l_new(struct wsc, 1);
>   	wsc->netdev = netdev;
>   
> 

Regards,
-Denis