Return-path: Received: from mail-bw0-f219.google.com ([209.85.218.219]:40823 "EHLO mail-bw0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750831AbZH2FWr (ORCPT ); Sat, 29 Aug 2009 01:22:47 -0400 Received: by bwz19 with SMTP id 19so1937622bwz.37 for ; Fri, 28 Aug 2009 22:22:48 -0700 (PDT) To: tim.gardner@canonical.com Cc: Johannes Berg , reinette chatre , "linville\@tuxdriver.com" , "linux-wireless\@vger.kernel.org" Subject: Re: [PATCH 1/2] cfg80211: initialize rate control after station inserted References: <1251416094-10420-1-git-send-email-reinette.chatre@intel.com> <1251445557.4189.14.camel@johannes.local> <1251474321.3805.73.camel@rc-desk> <1251493298.3456.34.camel@johannes.local> <4A984EBA.9040608@canonical.com> From: Kalle Valo Date: Sat, 29 Aug 2009 08:22:46 +0300 In-Reply-To: <4A984EBA.9040608@canonical.com> (Tim Gardner's message of "Fri\, 28 Aug 2009 15\:40\:10 -0600") Message-ID: <874orrjis9.fsf@litku.valot.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Tim Gardner writes: >> Interesting. I've been thinking about making it go the other way -- >> remove rate scaling hooks completely. wl1271 apparently has rate scaling >> completely in the firmware, so the RS algorithm on the host is just >> overhead. I've been thinking putting 4965+ RS into the _driver_ makes >> more sense since it really does a lot in the firmware and not on the >> host. >> >> Do you think we should try to go that route? I'd think it would probably >> be a hardware flag ("no RS algo please") and then we'd skip all the >> hooks and put things into the driver. The advantage is that we don't >> care about the mac80211 API any more, things get cleaner and we can just >> do all RS init from sta_notify(). >> > > Wouldn't that make it difficult to experiment with external rate > scaling algorithms? Not that minstrel or the other in-driver rate > scaling algorithms always get it right, but they are certainly more > transparent (and changeable) then firmware. In wl1271 you are forced to use the rate scaling algorithm from the firmware. IIRC tx descriptor doesn't even have a field for the bitrate. -- Kalle Valo