From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 1/3] backlight: Allow drivers to update the core, and generate events on changes Date: Wed, 29 Jul 2009 17:05:24 +0200 Message-ID: <20090729150524.GD1534@ucw.cz> References: <1247517685-7719-1-git-send-email-mjg@redhat.com> <1247574573.23871.8.camel@dax.rpnet.com> <1247644518.26272.88.camel@rzhang-dt> <1247646153.6248.3.camel@dax.rpnet.com> <1247647105.26272.99.camel@rzhang-dt> <1247649089.20241.5.camel@dax.rpnet.com> <20090715135808.GA19054@srcf.ucam.org> <1247711974.26272.190.camel@rzhang-dt> <20090716024057.GA2461@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:54032 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751494AbZG2PF2 (ORCPT ); Wed, 29 Jul 2009 11:05:28 -0400 Content-Disposition: inline In-Reply-To: <20090716024057.GA2461@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: Zhang Rui , Richard Purdie , "linux-kernel@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "lenb@kernel.org" , "corentincj@iksaif.net" > > > You want smoothing even in a default policy, and doing that well might > > > be a bit much for the kernel? > > > > > sorry, I don't understand. > > do you mean that there should be a default policy in the kernel? > > No, I mean that the only default policy you could reasonably have in the > kernel would be tying the backlight directly to the ALS. And that sucks. > You need some degree of smoothing, and that's a job better left to > userspace. How would that be done? Wake up userspace 100times a second so it can read an integer and ardd it to running average? Is ALS device stupid sensor, or can it do some smoothing/watermarks itself? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html