From: Johannes Berg <johannes@sipsolutions.net>
To: Larry Finger <Larry.Finger@lwfinger.net>
Cc: "John W. Linville" <linville@tuxdriver.com>,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH] b43: Fix locking problem when stopping rfkill polling
Date: Thu, 08 Oct 2009 00:36:55 +0200 [thread overview]
Message-ID: <1254955015.3713.9.camel@johannes.local> (raw)
In-Reply-To: <4ACCEBE8.8010803@lwfinger.net>
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On Wed, 2009-10-07 at 14:28 -0500, Larry Finger wrote:
> > OK, but why do we start polling under the lock but stop polling without
> > the lock? Should we start polling without holding the lock too?
>
> I'll test that, but I suspect it doesn't matter. Of course, the reason
> I put the stop under the lock was for symmetry, but then I got the
> following when shutting down:
>
> b43-phy0 debug: Removing Interface type 2
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.32-rc3-wl #225
> -------------------------------------------------------
> modprobe/25391 is trying to acquire lock:
> (&(&rfkill->poll_work)->work){+.+...}, at: [<ffffffff81054a7f>]
> __cancel_work_timer+0xd9/0x224
This is because when stopping polling we need to cancel the work and
sync on it, but when starting it's completely async so starting can be
in any context.
johannes
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next prev parent reply other threads:[~2009-10-07 22:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-07 15:06 [PATCH] b43: Fix locking problem when stopping rfkill polling Larry Finger
2009-10-07 19:01 ` John W. Linville
2009-10-07 19:28 ` Larry Finger
2009-10-07 19:46 ` Michael Buesch
2009-10-07 22:36 ` Johannes Berg [this message]
2009-10-07 22:43 ` Larry Finger
2009-10-07 23:08 ` Michael Buesch
2009-10-08 20:23 ` Larry Finger
2009-10-08 22:31 ` John W. Linville
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