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From: Oliver Neukum <oneukum@suse.de>
Organization: Novell
To: Alan Stern <stern@rowland.harvard.edu>
Subject: Re: refcounting drivers' data structures used in sysfs buffers
Date: Mon, 12 Mar 2007 19:25:00 +0100
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Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
       Maneesh Soni <maneesh@in.ibm.com>, gregkh@suse.de,
       linux-kernel@vger.kernel.org
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Am Montag, 12. März 2007 17:21 schrieb Alan Stern:
> On Mon, 12 Mar 2007, Oliver Neukum wrote:
> 
> > > > Yes, I was missing the point. In consequence, drivers must not use
> > > > dev_get_drvdata() to get their references to their private data. It's
> 
> You do realize how foolish that sounds?  Why do you think 
> dev_get_drvdata() was written in the first place?

It's still useful in disconnect/suspend/resume/etc...
If everything were alright with the design, we wouldn't be discussing
it now, would we?

 
> I'm with Dmitry; the whole thing becomes much, much simpler if we put back
> your patch and prevent sysfs access after unregistering an attribute 
> file.  No API changes are needed, no driver changes are needed, no radical 
> core changes are needed,...  All we would have to do is fix the one SCSI 
> method to make it use a workqueue.

Try. I don't like reverting my own code. But I predict he'll tell you that a
driver's bond with a device should be represented in a data structure
that is to be refcounted.

	Regards
		Oliver