From: Andrey Borzenkov <arvidjaar@mail.ru>
To: Richard Purdie <rpurdie@rpsys.net>
Subject: Re: 2.6.30: hald crashes on resume from STR apparently on LED device
Date: Sun, 28 Jun 2009 00:34:48 +0400
User-Agent: KMail/1.12.0 (Linux/2.6.30-desktop-2mnb; KDE/4.2.95; x86_64; ; )
Cc: hal@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <200906142219.06891.arvidjaar@mail.ru> <200906211817.25878.arvidjaar@mail.ru> <1245679044.10200.17.camel@dax.rpnet.com>
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On Monday 22 of June 2009 17:57:24 Richard Purdie wrote:
> On Sun, 2009-06-21 at 18:17 +0400, Andrey Borzenkov wrote:
> > So what happens is simple. During suspend led device is removed;
> > during resume it is recreated. Apparently removing led device cause
> > hald-addon- leds to exit (thus disconnecting D-Bus connection); and
> > sometimes next "add" event comes too early, before hald had chance
> > to notice missing addon.
>
> Note that its the underlying device that is being removed here and
> since the LED is connected to that its removed as well. The LED
> subsystem hasn't changed in how it works. I don't think that has any
> bearing on your patch though.
>

Yes, looking more closely there is inherent race condition between=20
tearing down existing helper and processing ADD event for it. Most=20
likely some timing was changed in current kernel that made it more=20
easily exposed. If Mandriva had not compiled D-Bus with assertions=20
enabled, this would simply fail silently without anyone noticing.

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