From owner-svn-src-head@FreeBSD.ORG Sun Jul 27 20:10:45 2014 Return-Path: Delivered-To: svn-src-head@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 3AD18E3A; Sun, 27 Jul 2014 20:10:45 +0000 (UTC) Received: from mail.turbocat.net (mail.turbocat.net [IPv6:2a01:4f8:d16:4514::2]) (using TLSv1.1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id EDED62176; Sun, 27 Jul 2014 20:10:44 +0000 (UTC) Received: from laptop015.home.selasky.org (cm-176.74.213.204.customer.telag.net [176.74.213.204]) (using TLSv1 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 725071FE027; Sun, 27 Jul 2014 22:10:42 +0200 (CEST) Message-ID: <53D55CD9.4000408@selasky.org> Date: Sun, 27 Jul 2014 22:11:05 +0200 From: Hans Petter Selasky User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Adrian Chadd Subject: Re: svn commit: r269127 - head/sys/dev/usb/wlan References: <201407261606.s6QG61le092895@svn.freebsd.org> <53D3FDEC.5040000@selasky.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Jul 2014 20:10:45 -0000 On 07/27/14 02:10, Adrian Chadd wrote: > On 26 July 2014 12:13, Hans Petter Selasky wrote: >> On 07/26/14 20:36, Adrian Chadd wrote: >>> >>> Hi, >>> >>> We should likely review how the PLCP bits are being used and why it's >>> getting a rate of 0 in the first place. >>> >>> So, why's it getting a rate of 0 passed into the transmit path? >>> >>> >> >> Hi Adrian, >> >> Here is the backtrace of the panic: >> >> Fatal trap 18: integer divide fault while in kernel mode >> cpuid = 2; apic id = 02 >> instruction pointer = 0x20:0xffffffff807826cf >> stack pointer = 0x28:0xffffff8000305090 >> frame pointer = 0x28:0xffffff80003050a0 >> code segment = base 0x0, limit 0xfffff, type 0x1b >> = DPL 0, pres 1, long 1, def32 0, gran 1 >> processor eflags = interrupt enabled, resume, IOPL = 0 >> current process = 15 (usbus0) >> trap number = 18 >> panic: integer divide fault >> cpuid = 2 >> KDB: stack backtrace: >> #0 0xffffffff809257e6 at kdb_backtrace+0x66 >> #1 0xffffffff808eb3ae at panic+0x1ce >> #2 0xffffffff80cd2c30 at trap_fatal+0x290 >> #3 0xffffffff80cd3480 at trap+0x250 >> #4 0xffffffff80cbc783 at calltrap+0x8 >> #5 0xffffffff80783d90 at ural_start+0x1d0 >> #6 0xffffffff809aa2ea at if_transmit+0xea >> #7 0xffffffff809ef7b2 at ieee80211_start+0x542 >> #8 0xffffffff809aa2ea at if_transmit+0xea >> #9 0xffffffff809ae8b3 at ether_output_frame+0x33 >> #10 0xffffffff809aee30 at ether_output+0x530 >> #11 0xffffffff80a186b4 at ip_output+0xd74 >> #12 0xffffffff80a87d2a at tcp_output+0xfea >> #13 0xffffffff80a82222 at tcp_do_segment+0xc02 >> #14 0xffffffff80a85219 at tcp_input+0xa29 >> #15 0xffffffff80a155fa at ip_input+0xaa >> #16 0xffffffff809b7808 at netisr_dispatch_src+0x218 >> #17 0xffffffff809ae3fd at ether_demux+0x14d > > Hm, so at some point that rate was not assigned to something. Can you > trace the ural_start path to see where it's supposed to be calculating > the rate? > Rate comes from this: tp = &vap->iv_txparms[ieee80211_chan2mode(ni->ni_chan)]; if (IEEE80211_IS_MULTICAST(wh->i_addr1)) rate = tp->mcastrate; else if (tp->ucastrate != IEEE80211_FIXED_RATE_NONE) rate = tp->ucastrate; else rate = ni->ni_txrate; --HPS