On Thursday 30 July 2009 17:37:09 Johannes Berg wrote:
> On Thu, 2009-07-30 at 10:45 -0400, Bob Copeland wrote:
> > On Thu, Jul 30, 2009 at 10:31 AM, Michael Buesch<mb@xxxxxxxxx> 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).
>
> > > [ 1669.800493] [<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?
>
> Indeed. I think this means we need to convert the local->sta_lock back
> to _irqsave/restore.
>
> John, can you revert the BH patch ("mac80211: do not use irq locks where
> not necessary") and I'll send a new one with those changes removed?
I didn't look at the code, but can't we simply request the beacon from
mac80211 before locking? Or isn't the spin_lock_irqsave() done in the driver?
--
Greetings, Michael.
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
