Re: [PATCH v3 07/11] mac80211: add HE 6 GHz Band Capability IE in Assoc. Request

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2020-05-13 at 12:45 -0700, Rajkumar Manoharan wrote:

> +int mesh_add_he_6ghz_cap_ie(struct ieee80211_sub_if_data *sdata,
> +			    struct sk_buff *skb)
> +{
> +	const struct ieee80211_sta_he_cap *he_cap;
> +	struct ieee80211_supported_band *sband;
> +	u8 ie_len;
> +	u8 *pos;
> +
> +	sband = ieee80211_get_sband(sdata);
> +	if (!sband)
> +		return -EINVAL;
> +
> +	he_cap = ieee80211_get_he_iftype_cap(sband, NL80211_IFTYPE_MESH_POINT);
> +
> +	if (!he_cap ||
> +	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
> +	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
> +	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
> +		return 0;
> +
> +	if (!he_cap->has_he_6ghz)
> +		return 0;

I saw this before and thought it may actually exist, but it doesn't?

Like I said before though, there doesn't seem much point in this, if you
don't have 6 GHz then don't advertise those channels ...

>  static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
> @@ -4803,7 +4809,8 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
>  	if (!sband->ht_cap.ht_supported) {
>  		ifmgd->flags |= IEEE80211_STA_DISABLE_HT;
>  		ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
> -		ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
> +		if (sband->band != NL80211_BAND_6GHZ)
> +			ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
>  	}
>  
>  	if (!sband->vht_cap.vht_supported)
> @@ -5493,7 +5500,8 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
>  	if (req->flags & ASSOC_REQ_DISABLE_HT) {
>  		ifmgd->flags |= IEEE80211_STA_DISABLE_HT;
>  		ifmgd->flags |= IEEE80211_STA_DISABLE_VHT;
> -		ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
> +		if (sband->band != NL80211_BAND_6GHZ)
> +			ifmgd->flags |= IEEE80211_STA_DISABLE_HE;
>  	}

These changes really sort of belong more into the next patch, I guess?
Not sure.


>  	if (req->flags & ASSOC_REQ_DISABLE_VHT)
> diff --git a/net/mac80211/util.c b/net/mac80211/util.c
> index 5a33755c22f4..2bcebe672c0d 100644
> --- a/net/mac80211/util.c
> +++ b/net/mac80211/util.c
> @@ -2839,6 +2839,21 @@ u8 *ieee80211_ie_build_he_cap(u8 *pos,
>  	return pos;
>  }
>  
> +u8 *ieee80211_ie_build_he_6ghz_band_cap(u8 *pos, u16 he_6ghz_cap)
> +{
> +	__le16 cap = cpu_to_le16(he_6ghz_cap);
> +
> +	*pos++ = WLAN_EID_EXTENSION;
> +	*pos++ = 3;
> +	*pos++ = WLAN_EID_EXT_HE_6GHZ_BAND_CAP;
> +
> +	/* Fixed data */
> +	memcpy(pos, &cap, sizeof(cap));
> +	pos += sizeof(cap);
> +
> +	return pos;
> +}

You forgot SMPS, so this needs to be a bit different, but it's probably
better as a separate function since it's in multiple places, I guess
I'll combine our two patches.

johannes