From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH V6 1/2] introduce ALS sysfs class Date: Tue, 1 Sep 2009 15:41:44 +0200 Message-ID: <20090901134144.GA2028@ucw.cz> References: <1251789947.3483.215.camel@rzhang-dt> <1251793844.3483.228.camel@rzhang-dt> <20090901084306.GD9942@elf.ucw.cz> <200909012047.00606.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:50187 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752080AbZIAUJS (ORCPT ); Tue, 1 Sep 2009 16:09:18 -0400 Content-Disposition: inline In-Reply-To: <200909012047.00606.rjw@sisk.pl> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: Zhang Rui , Len Brown , Linux Kernel Mailing List , linux-acpi , Greg KH > > > 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. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html