From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from hub022-nj-4.exch022.serverdata.net ([206.225.164.187]:29437 "EHLO HUB022-nj-4.exch022.serverdata.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752814Ab2GXKs1 (ORCPT ); Tue, 24 Jul 2012 06:48:27 -0400 Message-ID: <500E7D76.9010205@posedge.com> (sfid-20120724_124831_404118_8308878B) Date: Tue, 24 Jul 2012 16:18:22 +0530 From: Mahesh Palivela MIME-Version: 1.0 To: Johannes Berg CC: "linville@tuxdriver.com" , "linux-wireless@vger.kernel.org" Subject: Re: [PATCH] cfg80211: 80MHz (11ac) regulatory change References: <952C5D5D0470AE4FB7D8A75C6ADC71CA0FCC5E3B@mbx022-e1-nj-10.exch022.domain.local> ,<1343048772.4584.18.camel@jlt3.sipsolutions.net> <952C5D5D0470AE4FB7D8A75C6ADC71CA0FCC704B@mbx022-e1-nj-10.exch022.domain.local> <1343120184.4415.16.camel@jlt3.sipsolutions.net> In-Reply-To: <1343120184.4415.16.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 07/24/2012 02:26 PM, Johannes Berg wrote: > 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. > Sorry. Switched to thunderbird now. >> 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. > I am thinking no need of above/below convention as the center frequency value itself we know. >>> + /* 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? > You mean to say other bits like HT40MINUS, HT40PLUS or even DFS? >>> + /* >>> + * 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. > Agree. I will change this. > johannes >