From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH V6 1/2] introduce ALS sysfs class
Date: Wed, 2 Sep 2009 23:12:58 +0200
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Cc: Zhang Rui <rui.zhang@intel.com>, Len Brown <lenb@kernel.org>,
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On Tuesday 01 September 2009, Pavel Machek wrote:
> 
> > > > IMO, 0 and -1 are not errors. they just suggest that the Ambient Light
> > > > illuminance is beyond the device support range, while the device is
> > > > still working normally.
> > > > what about exporting these values (0 and -1) to user space directly?
> > > 
> > > Returning 0 for "below" range and 99999999 for "above" range would be
> > > nice, yes. 
> > 
> > Why not 0 and "all ones" or 0 and -1.
> > 
> > Is there anything wrong with -1 in particular?
> 
> Normal people expect -1 to be less than 123, and output is in ascii. If
> you make it ((unsigned) ~0) I guess that becomes acceptable.

Well, "-1" is a perfectly valid alphanumerical representation of an int.
I don't really see the problem with the "-", unless we're talking about some
broken user space, that is.

Rafael
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