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From: David Brownell <david-b@pacbell.net>
To: Hans Verkuil <hverkuil@xs4all.nl>
Subject: Re: [PATCH v2] v4l2_device/v4l2_subdev: final (?) version
Date: Sat, 29 Nov 2008 18:56:51 -0800
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Cc: Linux and Kernel Video <video4linux-list@redhat.com>,
       "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
       "davinci-linux-open-source@linux.davincidsp.com" 
	<davinci-linux-open-source@linux.davincidsp.com>,
       linux-kernel@vger.kernel.org,
       Laurent Pinchart <laurent.pinchart@skynet.be>
References: <200811291852.41794.hverkuil@xs4all.nl> <200811291422.20155.david-b@pacbell.net> <200811300006.22080.hverkuil@xs4all.nl>
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On Saturday 29 November 2008, Hans Verkuil wrote:
> > > Are there some documented guidelines on when to use BUG_ON?
> >
> > Maybe there should be. ?I know I've seen flames from Linus on
> > the topic. ?Basically, treat it like a panic() where the system
> > must stop operation lest it catch fire or scribble all over the
> > (not-backed-up) disk ... if the system can keep running sanely,
> > then BUG() and friends are inappropriate.
> 
> I think it would be good to have some document about this, since
> from what I've seen from a quick scan I'm not the only one who uses
> it incorrectly. There is no documentation in the asm-generic/bug.h
> header and there is also no documentation on this in the Documentation
> directory.

Fair enough ... but the basic advice is still going to be "strongly
avoid ever calling BUG()".  

I'll send a patch along doing that.

- Dave


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