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Date: Thu, 30 Jul 2009 10:45:37 -0400
Message-ID: <b6c5339f0907300745l3e7ec63eu9819503c4e7766bb@mail.gmail.com>
Subject: Re: Ath5k/mac80211 triggers WARN_ON in kernel/softirq.c
From: Bob Copeland <me@bobcopeland.com>
To: Michael Buesch <mb@bu3sch.de>,
	Johannes Berg <johannes@sipsolutions.net>
Cc: jirislaby@gmail.com, mickflemm@gmail.com, lrodriguez@atheros.com,
	wireless <linux-wireless@vger.kernel.org>
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On Thu, Jul 30, 2009 at 10:31 AM, Michael Buesch<mb@bu3sch.de> wrote:
> Ath5k from today's compat-wireless triggers the following WARNing
> on hostapd startup.
> [ 1669.799870] ------------[ cut here ]------------
> [ 1669.799934] WARNING: at kernel/softirq.c:141 local_bh_enable_ip+0x8b/0xb0()

because ath5k calls ieee80211_beacon_get inside a spin_lock_irqsave()
and this is WARN_ON_ONCE(in_irq() || irqs_disabled).

> [ 1669.799982] Hardware name:
> [ 1669.800023] Modules linked in: ath5k mac80211 ath cfg80211
> [ 1669.800192] Pid: 24862, comm: hostapd Not tainted 2.6.30.2 #3
> [ 1669.800238] Call Trace:
> [ 1669.800287] ?[<ffffffff80248e3b>] ? local_bh_enable_ip+0x8b/0xb0
> [ 1669.800340] ?[<ffffffff802432f8>] warn_slowpath_common+0x78/0xd0
> [ 1669.800391] ?[<ffffffff8024335f>] warn_slowpath_null+0xf/0x20
> [ 1669.800441] ?[<ffffffff80248e3b>] local_bh_enable_ip+0x8b/0xb0
> [ 1669.800493] ?[<ffffffff807e0fef>] _spin_unlock_bh+0xf/0x20
> [ 1669.800564] ?[<ffffffffa0040b92>] ieee80211_beacon_get+0x2c2/0x2d0 [mac80211]

I guess this is the first victim of spin_lock_bh conversion?

-- 
Bob Copeland %% www.bobcopeland.com