linux-kernel - Re: [PATCH/RFC] remove irqs_disabled warning from local_bh

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Message-Id: <200806201801.09858.mb@bu3sch.de>
Date:	Fri, 20 Jun 2008 18:01:09 +0200
From:	Michael Buesch <mb@...sch.de>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Johannes Berg <johannes@...solutions.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Linux Kernel list <linux-kernel@...r.kernel.org>,
	David Ellingsworth <david@...ntd.dyndns.org>,
	linux-wireless <linux-wireless@...r.kernel.org>
Subject: Re: [PATCH/RFC] remove irqs_disabled warning from local_bh_enable

On Friday 20 June 2008 17:55:41 Ingo Molnar wrote:
> 
> * Michael Buesch <mb@...sch.de> wrote:
> 
> > On Friday 20 June 2008 17:27:48 Ingo Molnar wrote:
> > >  [<c012b361>] local_bh_enable_ip+0xd1/0xe0
> > >  [<c08d9f9f>] _spin_unlock_bh+0x2f/0x40
> > >  [<c0471b92>] vortex_timer+0xe2/0x3e0
> > 
> > > real bug or false positive?
> > 
> > Well, a timer runs with IRQs disabled, no? So this would be a bug.
> 
> indeed - agreed :) [no time for me to fix it, but can test any rfc patch.]

A quick workaround always is to convert the lock into an _irqsafe lock.
Although it introduces higher overhead (interrupt-wise), it prevents the bug.
A real fix would require to understand the locking in the driver, which I
don't, as I never looked at the driver. :)

-- 
Greetings Michael.
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