From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:52746 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758103Ab3BFV3y (ORCPT ); Wed, 6 Feb 2013 16:29:54 -0500 Message-ID: <1360186206.7910.75.camel@jlt4.sipsolutions.net> (sfid-20130206_222958_319448_C8B5FFAD) Subject: Re: [PATCH 5/7] mac80211: Expand powersave configuration flag to be two bits From: Johannes Berg To: Seth Forshee Cc: linux-wireless@vger.kernel.org, "John W. Linville" , Stanislaw Gruszka , "Luis R. Rodriguez" , Jouni Malinen , Vasanthakumar Thiagarajan , Senthil Balasubramanian , Christian Lamparter , Ivo van Doorn , Gertjan van Wingerde , Helmut Schaa , Larry Finger , Chaoming Li , Arend van Spriel , Luciano Coelho , ath9k-devel@venema.h4ckr.net, brcm80211-dev-list@broadcom.com, users@rt2x00.serialmonkey.com Date: Wed, 06 Feb 2013 22:30:06 +0100 In-Reply-To: <20130206180227.GB6280@thinkpad-t410> References: <1359503255-18270-6-git-send-email-seth.forshee@canonical.com> <1359645648.8415.77.camel@jlt4.sipsolutions.net> <20130131163355.GE28799@thinkpad-t410> <1359651229.8415.99.camel@jlt4.sipsolutions.net> <20130131171826.GG28799@thinkpad-t410> <1359654634.8415.101.camel@jlt4.sipsolutions.net> <20130205225101.GB29557@thinkpad-t410> <1360169290.7910.29.camel@jlt4.sipsolutions.net> <20130206170952.GA6280@thinkpad-t410> <1360172656.7910.60.camel@jlt4.sipsolutions.net> <20130206180227.GB6280@thinkpad-t410> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2013-02-06 at 12:02 -0600, Seth Forshee wrote: > > Ah, wl1251 is the weird thing that wants to be told when to wake up/go > > to sleep, and then sends nulldata packets itself ... so when we send > > nulldata packets *again* for off-channel, because it also uses software > > scanning. Like I said before -- "stupidest powersave implementation on > > the planet". > > Ah, I had wondered what hardware that code was there for :-) I was actually wrong -- wl1251 has HW scan so it doesn't matter. However, iwlegacy does this... > So I think the approach I'm advocating could possibly make things better > for wl1251. If it's told about going to off-channel powersave rather > than being told it's leaving powersave, maybe it can do the right thing > with the nullfunc frames without mac80211 generating the extra nullfunc. > I don't know that for sure though because I don't understand how the > hardware works. Probably not. For iwlegacy anyway it won't help. > > > So using these definition powersave is already a mandatory feature for > > > any hardware which uses software scanning. > > > > Even offloaded scanning, it's just not visible to mac80211 then. > > Okay, sure. I'm just thinking of things from the mac80211 perspective. Right, sure. > > > All I'm really doing is > > > making this explicit, and drivers would now opt in to being placed into > > > the doze state rather than opting into powersave in general. And of > > > course drivers are now told about transitions to the non-doze powersave > > > state (what I'm calling offchannel), so that drivers which need to do > > > hardware configuration for this state can do so. > > > > Ok, so maybe just calling it offchannel makes more sense, although that > > really interacts only this way with powersave in managed mode, in P2P GO > > mode .... oh well. > > I admit I've only been considering managed mode and know next to nothing > about P2P GO mode. If I'm creating problems for any other modes I'd > definitely like to know about it so I can take it into consideration. No no, I'm just saying there "powersave" could have even more meanings ... johannes