From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wg0-f48.google.com ([74.125.82.48]:62289 "EHLO mail-wg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751818AbaEWGQM convert rfc822-to-8bit (ORCPT ); Fri, 23 May 2014 02:16:12 -0400 Received: by mail-wg0-f48.google.com with SMTP id k14so125256wgh.7 for ; Thu, 22 May 2014 23:16:10 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1400770304.4174.34.camel@jlt4.sipsolutions.net> References: <1400767676-15994-1-git-send-email-michal.kazior@tieto.com> <1400767676-15994-3-git-send-email-michal.kazior@tieto.com> <1400770304.4174.34.camel@jlt4.sipsolutions.net> Date: Fri, 23 May 2014 08:16:10 +0200 Message-ID: (sfid-20140523_081617_078189_A7F4F138) Subject: Re: [PATCH v6 2/6] mac80211: implement multi-vif in-place reservations From: Michal Kazior To: Johannes Berg Cc: linux-wireless , Luca Coelho Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 22 May 2014 16:51, Johannes Berg wrote: > On Thu, 2014-05-22 at 16:07 +0200, Michal Kazior wrote: > >> This introduces a special hook >> ieee80211_vif_chanctx_reservation_complete(). This >> is currently an empty stub and will be filled in >> by AP/STA CSA code. This is required to implement >> 2-step CSA finalization. > > I really don't see any value in this - just put it into the patch > implementing it? Okay, I'll move it to the AP CSA patch then. >> + * The callback is optional for channel context based drivers but is >> + * required to support channel switching. The callback and can sleep. > > That probably belongs to the previous patch, but isn't even true there > or here afaict. Ah, rebasing.. >> +static int >> +ieee80211_vif_use_reserved_incompat(struct ieee80211_local *local, >> + struct ieee80211_chanctx *ctx, >> + const struct cfg80211_chan_def *chandef) >> +{ >> + struct ieee80211_sub_if_data *sdata, *tmp; >> + struct ieee80211_chanctx *new_ctx; >> + u32 changed = 0; >> + int err; >> + >> + lockdep_assert_held(&local->mtx); >> + lockdep_assert_held(&local->chanctx_mtx); >> + >> + if (!ieee80211_chanctx_all_reserved_vifs_ready(local, ctx)) >> + return 0; >> + >> + if (ieee80211_chanctx_num_assigned(local, ctx) != >> + ieee80211_chanctx_num_reserved(local, ctx)) { >> + wiphy_info(local->hw.wiphy, >> + "channel context reservation cannot be finalized because some interfaces aren't switching\n"); >> + err = -EBUSY; >> + goto err; >> } > > I don't think I understand that condition, it's it possible to switch > from two vifs using two channels to both using a single third one? I assume you have a case where max number of different channels is degraded (e.g. non-radar -> more restrictive radar combination) in mind, right? In that case this won't work with this code. Now that I think about it it also won't work with cross-swapping (2 chanctx are being swapped and some vifs try to interchange between). I'll have to re-think this a bit more. >> + ieee80211_recalc_chanctx_chantype(local, new_ctx); >> + ieee80211_recalc_smps_chanctx(local, new_ctx); >> + ieee80211_recalc_chanctx_min_def(local, new_ctx); > > vs. > >> - ieee80211_recalc_chanctx_chantype(local, ctx); >> - ieee80211_recalc_smps_chanctx(local, ctx); >> - ieee80211_recalc_radar_chanctx(local, ctx); >> - ieee80211_recalc_chanctx_min_def(local, ctx); > > Did I miss something? Maybe it would be good to squeeze in that patch > that made a recalc_all() function to call all of these. The radar is now calculated in the _incompat manually because it should be saying "radar" before you call into switch_vif_chanctx/create new chanctx. I mean, you could initially bind a chanctx with ch52 without radar flag and then update it right away but it didn't sit right with me. Michał