Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:60410 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755158Ab1KHP6y (ORCPT ); Tue, 8 Nov 2011 10:58:54 -0500 Subject: Re: [PATCH v3 1/3] nl80211: Add probe response offload attribute From: Johannes Berg To: Arik Nemtsov Cc: Jouni Malinen , linux-wireless@vger.kernel.org In-Reply-To: (sfid-20111108_165440_062522_2707F77D) References: <1320762928-6782-1-git-send-email-arik@wizery.com> <1320766291.24797.4.camel@jlt3.sipsolutions.net> (sfid-20111108_165440_062522_2707F77D) Content-Type: text/plain; charset="UTF-8" Date: Tue, 08 Nov 2011 16:58:48 +0100 Message-ID: <1320767928.24797.14.camel@jlt3.sipsolutions.net> (sfid-20111108_165857_732994_E8049B8D) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, 2011-11-08 at 17:53 +0200, Arik Nemtsov wrote: > On Tue, Nov 8, 2011 at 17:31, Johannes Berg wrote: > > On Tue, 2011-11-08 at 16:35 +0200, Arik Nemtsov wrote: > >> Notify user-space about probe-response offloading support in the driver. > >> > >> A wiphy flag is used to indicate support and a bitmap of protocols > >> determines which protocols are supported. > > > >> + * @NL80211_ATTR_PROBE_RESP_OFFLOAD_SUPPORT: Indicates support for probe > >> + * response offloading by the driver/firmware. > >> + * In addition this attribute holds a bitmap of the supported protocols > >> + * for offloading using &enum nl80211_probe_resp_offload_support_attr. > > > > I wonder if this should make it more clear that probe requests will be > > replied to, and this is not optional? > > Actually wl12xx "supports" the legacy way as well. We can operate > without wpa_s explicitly setting the probe-resp (even though we just > piece it together in other ways). > In this sense, it's not a mandatory feature. If wpa_s fails to > generate it for some reason, we don't want it to fail the AP load. The > AP will operate just fine. It'll operate, not sure about "just fine" :-) The way I see it that's mostly a backward compatibility feature, no? > >> +++ b/include/net/cfg80211.h > >> @@ -1693,6 +1693,7 @@ enum wiphy_flags { > >> WIPHY_FLAG_AP_UAPSD = BIT(14), > >> WIPHY_FLAG_SUPPORTS_TDLS = BIT(15), > >> WIPHY_FLAG_TDLS_EXTERNAL_SETUP = BIT(16), > >> + WIPHY_FLAG_SUPPORT_PROBE_RESP_OFFLOAD = BIT(17), > > > > Ditto here, maybe WIPHY_FLAG_HAS_PROBE_RESP_OFFLOAD? > > > > As we discussed, ath6kl & similar full-mac drivers with AP SME in the > > device should set this to advertise the probe protocol feature set they > > support (by passing up), and even for wl12xx it's not optional. > > All this has to do with user-space semantics. Currently hostap always > sets the probe-resp IEs, without checking offloading support. Which is fine too, but I think ath6kl should set this value right? johannes