From owner-freebsd-wireless@FreeBSD.ORG Wed Aug 20 23:55:08 2014 Return-Path: Delivered-To: freebsd-wireless@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B56B6BFF; Wed, 20 Aug 2014 23:55:08 +0000 (UTC) Received: from mail-qg0-x231.google.com (mail-qg0-x231.google.com [IPv6:2607:f8b0:400d:c04::231]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 647D435BE; Wed, 20 Aug 2014 23:55:08 +0000 (UTC) Received: by mail-qg0-f49.google.com with SMTP id j107so7976864qga.8 for ; Wed, 20 Aug 2014 16:55:07 -0700 (PDT) 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:content-type; bh=UARrdg1tP5tdhtGWYTH4BRv+aHLsdr4WXKa3pSL2WtQ=; b=D2/jimhBpsomkUIg5bzHm9s+87KXWrU3mDoF9U+d137X5bS0h79fTNXl9y2RmO7rUF 8OG+Nj6TO8szEIOV2+p1Z9Or9kApj0HfsH6hAiXIiqAIpydpwfqQ9fsdNAZFIZqK1dxi dJpnvgrUu+OQlDWzfZJ1lg9WMb7HpPblFmQo25IjvSchAkO2+WB2+iIUVKp2BgX6X0IG 4p+I1g4g4HS2RC4U0WVFp1kpO8oMzC2LLJqHYITSszfn18W8dr19GjdiTRfQ/Lb87SZQ CkVLmQhkZnyO+H2mkEu1ylI+iSLxda8PyH/Enm+y7Ts4NOYITbQ2v+9g3bYU3JIG5fau baaA== MIME-Version: 1.0 X-Received: by 10.224.75.73 with SMTP id x9mr45870275qaj.63.1408578907625; Wed, 20 Aug 2014 16:55:07 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.224.39.139 with HTTP; Wed, 20 Aug 2014 16:55:07 -0700 (PDT) In-Reply-To: References: Date: Wed, 20 Aug 2014 16:55:07 -0700 X-Google-Sender-Auth: ZZGnLwYWzEx3sysy8sKCauQOdiI Message-ID: Subject: Re: FreeBSD current RT3071 can't connect to 5G network From: Adrian Chadd To: PseudoCylon Content-Type: text/plain; charset=UTF-8 Cc: Kevin Lo , "freebsd-wireless@freebsd.org" X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Discussions of 802.11 stack, tools device driver development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Aug 2014 23:55:08 -0000 On 20 August 2014 16:33, PseudoCylon wrote: > On Wed, Aug 20, 2014 at 1:29 PM, Adrian Chadd wrote: >> Are you seeing RX CRC errors for all rates? CCK? OFDM? HT? At all distances? > > CCK not sure, OFDM and HT yes. And at wide range of distances. (Tx > rates usually hit mcs 12 to 14 with 2s ht20 ap) > >> >> There's a handful of things we can look at to see what's causing it >> once some more digging is done. >> >> (Eg, HT? could be guard interval. OFDM has similar issues, there's >> typically ways to configure how much time between each symbol is left >> before transmitting the next one. It may not be doing CTS-to-self, or >> it may not be advertising the right thing via NAV, or it may be >> ignoring CCK, or the receive gain tables are all messed up, etc.) > > I have looked into stuff I was able to dig out from other src codes, > ie protection, ifs, nav, bk slot. (Because I do not have datasheet, > every thing is based on my guesses.) One thing I could not figure out > is if on-chip memory is properly allocated for rx pkt. (It seems > memory can be allocated for different things, ie beacon, enc keys). > So CRC errors are pretty normal with wifi. Even a tiny bit of interference generates CRC errors. That's why there's an ACK and retry mechanism. :P If you're hitting MCS 12 then you're doing pretty well. A-MPDU will see lots of CRC errors just because of how long the transmissions are and how easily corrupted things can get. That's again why there's a quick retry mechanism for things. What %age errors are you seeing? -a