Date: Wed, 6 May 2009 11:36:55 +0530
From: Vasanthakumar Thiagarajan <vasanth@atheros.com>
To: "Luis R. Rodriguez" <mcgrof@gmail.com>
CC: linux-wireless <linux-wireless@vger.kernel.org>,
	Johannes Berg <johannes@sipsolutions.net>,
	Vasanth Thiagarajan <Vasanth.Thiagarajan@Atheros.com>
Subject: Re: oops during stress test - today's wl
Message-ID: <20090506060646.GF18158@vasanth-laptop>
References: <43e72e890905042005vb96f57aid70c476e38685dfe@mail.gmail.com> <1241509306.25337.4.camel@johannes.local> <43e72e890905051227n11b128bap4d250e66294a29ce@mail.gmail.com> <43e72e890905051829k5df86692m34209f871e384127@mail.gmail.com>
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On Wed, May 06, 2009 at 06:59:02AM +0530, Luis R. Rodriguez wrote:
> On Tue, May 5, 2009 at 12:27 PM, Luis R. Rodriguez <mcgrof@gmail.com> wrote:
> > On Tue, May 5, 2009 at 12:41 AM, Johannes Berg
> > <johannes@sipsolutions.net> wrote:
> >> On Mon, 2009-05-04 at 20:05 -0700, Luis R. Rodriguez wrote:
> >>> mcgrof@pogo ~/wireless-testing (git::master)$ git-describe
> >>> v2.6.30-rc4-22720-gb2382a4
> >>>
> >>> While running iperf, after about 1 hour.
> >>>
> >>> http://bombadil.infradead.org/~mcgrof/oops-img/09-05/oops-01-v2.6.30-rc4-22720-gb2382a4.jpg
> >>>
> >>> Image probably doesn't help much.. but its what I got.. I'd look more
> >>> but its getting late here, so I'm out. I'll use netconsole tomorrow.
> >>
> >> Yeah, doesn't really help... I would suspect the driver to be honest,
> >> since the scan code is trying to TX a frame and it's already in
> >> ieee80211_tx() (and probably in __ieee80211_tx which gets inlined).
> >
> > Right on --
> >
> > [57158.757990] wlan1: no probe response from AP 00:03:7f:0c:c2:5d -
> > disassociating
> > [57559.563565] cfg80211: Found new beacon on frequency: 5200 MHz (Ch 40) on phy2
> > [57559.669684] cfg80211: Found new beacon on frequency: 5220 MHz (Ch 44) on phy2
> > [57563.415178] cfg80211: Found new beacon on frequency: 5745 MHz (Ch
> > 149) on phy2
> > [57563.478395] cfg80211: Found new beacon on frequency: 5765 MHz (Ch
> > 153) on phy2
> > [57563.737684] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [57563.754972] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [57563.763958] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [57563.765895] wlan1: authenticated
> > [57563.765930] wlan1: associate with AP 00:03:7f:0c:c2:5d
> > [57563.779535] wlan1: RX ReassocResp from 00:03:7f:0c:c2:5d
> > (capab=0x421 status=0 aid=1)
> > [57563.779595] wlan1: associated
> > [57633.747150] wlan1: deauthenticating by local choice (reason=3)
> > [57634.224023] wlan1: deauthenticating by local choice (reason=3)
> > [57654.246527] ADDRCONF(NETDEV_UP): wlan1: link is not ready
> > [57659.942571] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [57659.945696] wlan1: authenticated
> > [57659.945735] wlan1: associate with AP 00:03:7f:0c:c2:5d
> > [57659.951992] wlan1: RX AssocResp from 00:03:7f:0c:c2:5d (capab=0x421
> > status=0 aid=1)
> > [57659.952054] wlan1: associated
> > [57659.962379] ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
> > [57670.356717] wlan1: no IPv6 routers present
> > [58264.676456] wlan1: deauthenticated (Reason: 2)
> > [58265.671832] wlan1: direct probe to AP 00:03:7f:0c:c2:5d try 1
> > [58265.671832] wlan1: direct probe to AP 00:03:7f:0c:c2:5d try 1
> > [58265.881845] wlan1: direct probe to AP 00:03:7f:0c:c2:5d try 2
> > [58265.881845] wlan1: direct probe to AP 00:03:7f:0c:c2:5d try 2
> > [58265.887928] wlan1 direct probe responded
> > [58265.887966] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [58265.887928] wlan1 direct probe responded
> > [58265.887966] wlan1: authenticate with AP 00:03:7f:0c:c2:5d
> > [58265.890837] wlan1: authenticated
> > [58265.890871] wlan1: associate with AP 00:03:7f:0c:c2:5d
> > [58265.890837] wlan1: authenticated
> > [58265.890871] wlan1: associate with AP 00:03:7f:0c:c2:5d
> > [58265.898987] wlan1: RX ReassocResp from 00:03:7f:0c:c2:5d
> > (capab=0x421 status=0 aid=1)
> > [58265.899041] wlan1: associated
> > [58265.898987] wlan1: RX ReassocResp from 00:03:7f:0c:c2:5d
> > (capab=0x421 status=0 aid=1)
> > [58265.899041] wlan1: associated
> > [58266.391122] ------------[ cut here ]------------
> > [58266.391166] kernel BUG at drivers/net/wireless/ath/ath9k/rc.c:746!
> > [58266.391202] invalid opcode: 0000 [#1] PREEMPT SMP
> > [58266.391253] last sysfs file:
> > /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
> > [58266.391303] CPU 3
> > [58266.391333] Modules linked in: netconsole ath9k configfs ipv6
> > cpufreq_ondemand powernow_k8[58266.391122] ------------[ cut here
> > ]------------
> >  freq_table binfmt_misc loop dm_multipath scsi_dh arc4 ecb mac80211
> > rfkill af_packet led_class ath sr_mod cfg80211 e1000 evdev shpchp
> > cdrom evbug[58266.391166] kernel BUG at
> > drivers/net/wireless/ath/ath9k/rc.c:746!
> 
> This is this assert:
> 
>         ASSERT((rate_table->info[rate].valid &&
>                 (ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)) ||
>                (rate_table->info[rate].valid_single_stream &&
>                 !(ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)));
> 

This is odd. Hitting this assert means that we have selected a wrong
rate index wrt the type of stream. There may be a bug in rc init
which gets exposed after assoc/reassoc and disassoc.

> What's this WLAN_RC_DS_FLAG? I see we set it if our hardware supports
> ATH9K_CAP_DS, the current tx_chainmask is not 1 (which in turn we get
> from the EEPROM), and.. if sta->ht_cap.mcs.rx_mask[1]..

WLAN_RC_DS_FLAG means the rate control is going to be initialized
with dual stream rates.

> 
> I see rate private structure
> for the sta gets updated during get rate but there is no locking for
> this but I also don't see dire consequences for this yet.

This is protected by rcu_read_lock()?


Vasanth