From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-x22b.google.com (mail-ig0-x22b.google.com [IPv6:2607:f8b0:4001:c05::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id B923D3B2C4; Sat, 12 Mar 2016 15:18:14 -0500 (EST) Received: by mail-ig0-x22b.google.com with SMTP id av4so36244129igc.1; Sat, 12 Mar 2016 12:18:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc; bh=nJ11rsMQhZeRwfRpWFm8aEX7p6Mf4B4C6N0lpngMzvE=; b=sAQ6hW8DJaulByFsx6jOmQXqxjRn6y/hDl1zcUWJmsng6/UoltzTm3LFsiSSyaEjLS gK20lLXeRsJFrpngND+JsghHydNaDJV0ceYm6ERwb4JnZastogRwzNfImHq4UyMALrO3 +2VGFfelQk6pnBzMGJJ8hnWQvjeIxLfAkwhRvaRoiyIH3hcn7ZSVmZ1A9Bj1Yv5QEKfj uQZmlIbGdanxrIMRyAzPiIm0gDiIVBTNVQhl39VH7A8n8bRKU0Bh2ot8Ls/H5Gf9YQLw geVDsTYElXjf5yLk9swKaIzlcd+Y/INAeFJTRSf5jKTOasgKpJcp5ujja3jMA4GRxHdB Y3kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to:cc; bh=nJ11rsMQhZeRwfRpWFm8aEX7p6Mf4B4C6N0lpngMzvE=; b=mQ5NrPpgrHviIrcYKOkNiXXunmoOFysPRaS2gw31nTjkNhyhADwAmv8TARU3OJD6tW kAZ59BsPz9cdfwBWLXvRZgSoXecPUQiVRio5zAcw6ZrjQxU/0COwIGNX6FvFTZXMqtEG xv8tRAmmXiclAYfKENQhT/ect41W4b87EaWDUNKDflSjfXQa1GeWSPQzLMB3cIOuGnr8 NUwaxKmVN+k6l3yLd0PbwuZTJjpuTRlj6LElOLtjcknvb5SkYqsZkglx9X9KMyjRqznH GdzMSw8BFZ9Iex91hQ6f//YRBjJ8hQPyMWHEOMXVuWJT3Apa7YgHpuEmQRZV6542jIbi egPA== X-Gm-Message-State: AD7BkJJ3Sl10QIt3Y1n+l5Z3MKZkg3aSdnBhC9Wq1NmmPdG/rA7b7Urx1c/jeByFx2BzmHRt1e51jlMEVqSJVw== MIME-Version: 1.0 X-Received: by 10.50.78.200 with SMTP id d8mr10010611igx.61.1457813894170; Sat, 12 Mar 2016 12:18:14 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.36.14.19 with HTTP; Sat, 12 Mar 2016 12:18:14 -0800 (PST) In-Reply-To: References: Date: Sat, 12 Mar 2016 12:18:14 -0800 X-Google-Sender-Auth: bCX-zMzpXgDlZ11aYwZX2ft_Of8 Message-ID: From: Adrian Chadd To: Henning Rogge Cc: Wayne Workman , make-wifi-fast@lists.bufferbloat.net, bufferbloat-fcc-discuss , "cerowrt-devel@lists.bufferbloat.net" Content-Type: text/plain; charset=UTF-8 X-Mailman-Approved-At: Wed, 16 Mar 2016 11:41:57 -0400 Subject: Re: [Make-wifi-fast] [bufferbloat-fcc-discuss] arstechnica confirms tp-link router lockdown X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Mar 2016 20:18:14 -0000 On 12 March 2016 at 11:14, Henning Rogge wrote: > On Sat, Mar 12, 2016 at 3:32 PM, Wayne Workman > wrote: >> I understand that Broadcom was paid to develop the Pi, a totally free board. >> >> And they already make wireless chipsets. > > The question is how easy would it be to build a modern 802.11ac > halfmac chip... the amount of work these chips do (especially with 3*3 > or 4*4 MIMO) is not trivial. It's not that scary - most of the latency sensitive things are: * channel change - eg background scans * calibration related things - but most slow calibration could be done via firmware commands, like the intel chips do! * transmit a-mpdu / retransmit * transmit rate control adaptation * receiving / block-ack things - which is mostly done in hardware anyway * likely some power save transition-y things too If you're doing STA mode, then you have more things to do - eg bgscans with active traffic, TDLS, P2P, etc. If you're doing hostap mode or heck, even mostly-dumb ibss mode - where there's no requirement for off-channel traffic - the firmware is mostly just a transmit/receive engine and some power save stuff. And honestly - know how many cycles a modern CPU has? If you don't care about hyper-optimising for power consumption (ie, you're not a phone), then I bet you could get away with ath9k model hardware. Those same lower end CPUs can do 200kpps on an ethernet NIC right now. The reordering and retransmit stuff could be handled in firmware, but that's about it - and again, only if you wanted to do it on some anenmic SoC or you cared about power. People keep talking about "oh god, these things do so much now" - but that's because people are thinking about phones or those L2-cache-less anemic older SOCs that are massively memory bandwidth constrained. Newer stuff is much less terrible. -adrian