From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:38430 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751947Ab2GXI4d (ORCPT ); Tue, 24 Jul 2012 04:56:33 -0400 Message-ID: <1343120184.4415.16.camel@jlt3.sipsolutions.net> (sfid-20120724_105637_552793_5A489D76) Subject: Re: [PATCH] cfg80211: 80MHz (11ac) regulatory change From: Johannes Berg To: Mahesh Palivela Cc: "linville@tuxdriver.com" , "linux-wireless@vger.kernel.org" Date: Tue, 24 Jul 2012 10:56:24 +0200 In-Reply-To: <952C5D5D0470AE4FB7D8A75C6ADC71CA0FCC704B@mbx022-e1-nj-10.exch022.domain.local> References: <952C5D5D0470AE4FB7D8A75C6ADC71CA0FCC5E3B@mbx022-e1-nj-10.exch022.domain.local> ,<1343048772.4584.18.camel@jlt3.sipsolutions.net> <952C5D5D0470AE4FB7D8A75C6ADC71CA0FCC704B@mbx022-e1-nj-10.exch022.domain.local> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: It would be really good if you could convince your email client to put > in front of each quoted line ... this is really confusing as is. > Also, I believe there are many more possibilities, since we count from > the control channel -- ie. for HT HT40+ means secondary channel is above > the control channel. For VHT 80, you're going to have 4 possibilities: > > |-1-|-2-|-3-|-4-| > > the control channel can be any one of these four I believe? So you'd > have configurations like > > VHT_CHAN_LAYOUT_0_3 > VHT_CHAN_LAYOUT_1_2 > VHT_CHAN_LAYOUT_2_1 > VHT_CHAN_LAYOUT_3_0 > > indicating the number of channels below/above control (for control > channel 1,2,3,4 respectively). Similarly, for VHT160 you'd have 8 > possibilities: > > |-1-|-2-|-3-|-4-|-5-|-6-|-7-|-8-| > > (which one could again capture as VHT_CHAN_LAYOUT_0_7 etc.) > > [MP] I see your point. But according to 11ac spec, AP will use primary > chan as specified in HT operation IE chan num. Secondary channel is > center freq specified in VHT Operation IE. So I am thinking secondary > channel is not relative offset to primary channel. Hope I am not > mistaken here. Ok so HT has primary channel and secondary, and VHT has secondary VHT which can again be above/below? That would make sense, but you wouldn't be covering it. > > + /* This would happen when regulatory rules disallow VHT80 completely */ > > + if (IEEE80211_CHAN_NO_VHT80 == (chan->flags & (IEEE80211_CHAN_NO_VHT80))) > > + return true; > > Is that really right? Need to document what the return value of this > function should be, I guess? > > [MP] I guess, it's possible for a channel not allowed for 80Mhz operation. Yeah but should it really check *all* the bits rather than any one of them? > > + /* > > + * Please note that this assumes target bandwidth is 40 MHz, > > + * if that ever changes we also need to change the below logic > > + * to include that as well. > > + */ > > ??? > > [MP] Can you explain? This function doesn't make any sense? The comment about 40 MHz doesn't make any sense. johannes