From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:36729 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932685Ab1KGRkp (ORCPT ); Mon, 7 Nov 2011 12:40:45 -0500 Message-ID: <4EB81817.9060300@candelatech.com> (sfid-20111107_184048_516868_05856B41) Date: Mon, 07 Nov 2011 09:40:39 -0800 From: Ben Greear MIME-Version: 1.0 To: Johannes Berg CC: linux-wireless@vger.kernel.org Subject: Re: [PATCH v4 1/2] wireless: Support ht-capabilities over-rides. References: <1320437440-6463-1-git-send-email-greearb@candelatech.com> (sfid-20111104_211056_032573_0C709B20) <1320656776.3993.21.camel@jlt3.sipsolutions.net> In-Reply-To: <1320656776.3993.21.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 11/07/2011 01:06 AM, Johannes Berg wrote: >> @@ -537,6 +539,12 @@ int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev, >> memcpy(&req.crypto, crypt, sizeof(req.crypto)); >> req.use_mfp = use_mfp; >> req.prev_bssid = prev_bssid; >> + req.flags = assoc_flags; >> + if (ht_capa) >> + memcpy(&req.ht_capa, ht_capa, sizeof(req.ht_capa)); >> + if (ht_capa_mask) >> + memcpy(&req.ht_capa_mask, ht_capa_mask, >> + sizeof(req.ht_capa_mask)); > > I think somewhere here you should mask this mask with the > ht_capa_mod_mask. That way, you force drivers to advertise a correct > ht_capa_mod_mask, if you don't do that we will certainly see drivers use > more of ht_capa than contained in ht_capa_mod_mask. Probably should be a > helper function since I think you might need it in more places. This goes back to how hard we want to be on user-space. If we are lax, and just ignore settings that are not (yet?) supported by the kernel, then user-space becomes much easier to make backwards/forwards compat. That is my preferred approach. In order for drivers (I assume you mean mac80211 as a driver) to support more stuff, then we will have to explicitly add more code there. At that point, the ht-capa-mod-mask will need to be updated to stay in sync. The mod-mask is going to live in mac80211 as far as I can tell, it seems valid to just keep them up to date in that manner and let user-space be oblivious to the mask *if it prefers*. If you feel strongly that we need to be very strict with user-space in this case, then please say so, and I'll quite arguing and code it up. It is going to make the hostapd code more complex, however. Thanks, Ben > > johannes -- Ben Greear Candela Technologies Inc http://www.candelatech.com