[PATCH] Enabling 802.11ac (VHT) mode

Jouni Malinen j at w1.fi
Sat Jul 23 10:22:13 PDT 2016

On Mon, Jun 13, 2016 at 04:53:08PM +0200, Jose Blanquicet wrote:
> When an AP is trying to be enabled in 802.11ac (VHT) mode by setting its 
> parameter disable_vht to 0, it is not actually enabled and it's set to HT. 
> Looking at the source code it was found that the variable used to check 
> whether to enable or not the VHT is ssid->vht but it has not been set 
> before. Instead, the variable ssid->disable_vht stores the actual network 
> parameter which indicates if the VHT has been disabled or not. 
> Is it OK? Or there is something I am missing to correctly set wpa_supplicant 
> in AC mode?

ssid->vht is used when setting up a P2P GO. However, it looks like the
configuration parser does not provide means for enabling this for
non-P2P use cases (i.e., when setting up an AP mode operation with

> diff --git a/wpa_supplicant/ap.c b/wpa_supplicant/ap.c
> @@ -166,7 +166,7 @@ int wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s,
> -			if (mode->vht_capab && ssid->vht) {
> +			if (mode->vht_capab && !ssid->disable_vht) {
>  				conf->ieee80211ac = 1;
>  				wpas_conf_ap_vht(wpa_s, conf, mode);
>  			}

This would break builds without CONFIG_VHT_OVERRIDES defined. In
addition, this would break the expected P2P behavior on how VHT is being
enabled. I guess it could be fine to make the non-P2P AP case enable VHT
automatically based on driver capabilities (and allow that to be
prevented that with ssid->disable_vht).
Jouni Malinen                                            PGP id EFC895FA

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