Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753472AbZIBVOf (ORCPT ); Wed, 2 Sep 2009 17:14:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752045AbZIBVOf (ORCPT ); Wed, 2 Sep 2009 17:14:35 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:44768 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbZIBVOe (ORCPT ); Wed, 2 Sep 2009 17:14:34 -0400 Date: Wed, 2 Sep 2009 23:14:15 +0200 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Zhang Rui , Len Brown , Linux Kernel Mailing List , linux-acpi , Greg KH Subject: Re: [PATCH V6 1/2] introduce ALS sysfs class Message-ID: <20090902211414.GA2789@elf.ucw.cz> References: <1251789947.3483.215.camel@rzhang-dt> <200909012047.00606.rjw@sisk.pl> <20090901134144.GA2028@ucw.cz> <200909022312.58494.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200909022312.58494.rjw@sisk.pl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1420 Lines: 33 On Wed 2009-09-02 23:12:58, Rafael J. Wysocki wrote: > 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. No. But if you see illumination value of -1 lumen, do you really expect a *lot* of light? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/