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From: Michael Buesch <mb@bu3sch.de>
To: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Berg <johannes@sipsolutions.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	David Ellingsworth <david@identd.dyndns.org>,
	linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH/RFC] remove irqs_disabled warning from local_bh_enable
Date: Fri, 20 Jun 2008 18:01:09 +0200	[thread overview]
Message-ID: <200806201801.09858.mb@bu3sch.de> (raw)
In-Reply-To: <20080620155541.GC6656@elte.hu>

On Friday 20 June 2008 17:55:41 Ingo Molnar wrote:
> 
> * Michael Buesch <mb@bu3sch.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.

  reply	other threads:[~2008-06-20 16:02 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-17 21:57 [PATCH/RFC] remove irqs_disabled warning from local_bh_enable Johannes Berg
2008-06-17 23:08 ` David Miller
2008-06-17 23:55 ` Linus Torvalds
2008-06-18  7:01   ` Peter Zijlstra
2008-06-18  7:29   ` Johannes Berg
2008-06-20 13:46     ` Ingo Molnar
2008-06-20 15:27       ` Ingo Molnar
2008-06-20 15:36         ` Michael Buesch
2008-06-20 15:55           ` Ingo Molnar
2008-06-20 16:01             ` Michael Buesch [this message]
2008-06-20 16:18               ` Michael Buesch
2008-06-23  8:41                 ` Ingo Molnar
2008-06-23  9:22                   ` Michael Buesch
2008-06-27  5:33                   ` Jeff Garzik
2008-06-27 10:53                     ` Ingo Molnar
2008-06-27 10:56                       ` Johannes Berg
2008-06-20 15:43         ` Johannes Berg
2008-06-20 15:46           ` Johannes Berg

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