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Date: Wed, 9 Jul 2008 22:04:44 +0100
From: Ben Dooks <ben-linux@fluff.org>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Ben Dooks <ben-linux@fluff.org>, dbaryshkov@gmail.com,
       linux-kernel@vger.kernel.org, linux-arm-kernel@lists.arm.linux.org.uk
Subject: Re: [patch 4/4] MFD: Change mfd platform device usage to wrapper platform_device
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On Wed, Jul 09, 2008 at 09:56:25PM +0100, Russell King - ARM Linux wrote:
> On Wed, Jul 09, 2008 at 11:49:20AM +0100, Ben Dooks wrote:
> > This patch changes the mfd core behaviour to wrapper the platform_device
> > it creates in an struct mfd_device which contains the information
> > about the cell that was created.
> 
> You can't do this.  Grab a reference to the platform device (by holding
> one of its sysfs files open) and then remove all the users of the mfd-core
> module and the mfd-core module itself.
> 
> Then, read from that file and close it.  Watch your kernel oops.
> 
> That's why device release methods inside modules are a BAD IDEA and why
> we have the platform device alloc API.

Would this be fixed by grabbing a reference to the mfd-core module whilst
the mfd device is open?

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.

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