From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: brightness control on thinkpad t61p Date: Tue, 8 Jan 2008 00:45:59 +0000 Message-ID: <20080108004559.GA27177@srcf.ucam.org> References: <20071223000057.739d5891.akpm@linux-foundation.org> <20071224073406.GA1018@srcf.ucam.org> <20071226141027.6d1a509f.akpm@linux-foundation.org> <20071226222321.GA32297@srcf.ucam.org> <20071227123358.GB25535@khazad-dum.debian.net> <20080107013623.GA6667@khazad-dum.debian.net> <20080107194833.GA22506@srcf.ucam.org> <20080108003246.GA15587@khazad-dum.debian.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([78.32.9.130]:43567 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752209AbYAHAqK (ORCPT ); Mon, 7 Jan 2008 19:46:10 -0500 Content-Disposition: inline In-Reply-To: <20080108003246.GA15587@khazad-dum.debian.net> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Henrique de Moraes Holschuh Cc: Andrew Morton , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" On Mon, Jan 07, 2008 at 10:32:46PM -0200, Henrique de Moraes Holschuh wrote: > Should we? Why? We lose information doing that. Instead of a nice linear > 0-100% brightness scale, you are now back to an 8 or 16-level non-linear > brightness scale. The spec makes no guarantees about what that 0-100 range means - it may be brightness, power consumption or bonghits. It's really not guaranteed to be meaningful, and the backlight class doesn't provide that guarantee either. -- Matthew Garrett | mjg59@srcf.ucam.org