Re: [PATCH] hostapd: Don't force HT Mixed Mode for non-GF STAs

[Helmut Schaa <helmut.schaa@googlemail.com>]

Am Mittwoch, 2. März 2011 schrieb Johannes Berg:
> On Wed, 2011-03-02 at 10:13 +0100, Helmut Schaa wrote:
> 
> > iwlwifi/iwllegacy seems correct (as long as the fw is doing the right thing):
> > 
> > 560 void iwlagn_bss_info_changed(struct ieee80211_hw *hw,
> > 561                              struct ieee80211_vif *vif,
> > 562                              struct ieee80211_bss_conf *bss_conf,
> > 563                              u32 changes)
> > 564 {
> > ...
> > 608                 ctx->ht.protection = bss_conf->ht_operation_mode &
> > 609                                         IEEE80211_HT_OP_MODE_PROTECTION;
> > 610                 ctx->ht.non_gf_sta_present = !!(bss_conf->ht_operation_mode &
> > 611                                         IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT);
> 
> Well, you forgot to quote this from iwl-agn-rs.c:
> 
> static bool rs_use_green(struct ieee80211_sta *sta)
> {
>         struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;   
>         struct iwl_rxon_context *ctx = sta_priv->common.ctx;
>   
>         return (sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD) &&
>                 !(ctx->ht.non_gf_sta_present);
> } 

Hmm, that looks a bit fishy as well. iwlagn should be allowed to use GF
in that case, it just needs to protect it.

> But it looks like it's doing the right thing.

>From a protection POV, yes.

Helmut