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From: David Brownell <david-b@pacbell.net>
To: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCHv2] at91: fix enable/disable_irq_wake symmetry in pcmcia driver
Date: Thu, 10 May 2007 23:01:56 -0700
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Cc: Marc Pignat <marc.pignat@hevs.ch>, andrew@sanpeople.com,
       linux-kernel@vger.kernel.org
References: <200705101009.36302.marc.pignat@hevs.ch> <20070510152636.4adb3ef1.akpm@linux-foundation.org>
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On Thursday 10 May 2007, Andrew Morton wrote:

> "disable_irq_wake call must be symmetric with enable_irq_wake".  hmm, OK,
> I'll take your word for it.

In the same way that enable_irq() and disable_irq() must be matched,
and for the same reasons:  when the IRQ is shared between drivers,
they can't all treat enable/disable status as boolean.  Those calls
mask refcountig.


> Does the present code actually fail in some manner, or what?

Yes ... runtime warnings flagging various misbehaviors associated
with refcount mismatches.

- Dave


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