Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753165AbZISXYZ (ORCPT ); Sat, 19 Sep 2009 19:24:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752749AbZISXYY (ORCPT ); Sat, 19 Sep 2009 19:24:24 -0400 Received: from out1.smtp.messagingengine.com ([66.111.4.25]:44915 "EHLO out1.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751026AbZISXYX (ORCPT ); Sat, 19 Sep 2009 19:24:23 -0400 X-Sasl-enc: Z0UpiP37Esr1fqfyHXiYziHW278wglP0pUE4R7y8aobi 1253402666 Date: Sat, 19 Sep 2009 20:24:24 -0300 From: Henrique de Moraes Holschuh To: Matthew Garrett Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rpurdie@rpsys.net, lenb@kernel.org, rui.zhang@intel.com, corentincj@iksaif.net Subject: Re: [PATCH 1/3] backlight: Allow drivers to update the core, and generate events on changes Message-ID: <20090919232424.GA15200@khazad-dum.debian.net> References: <1247587564-27737-1-git-send-email-mjg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1247587564-27737-1-git-send-email-mjg@redhat.com> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 28 On Tue, 14 Jul 2009, Matthew Garrett wrote: > Certain hardware will send us events when the backlight brightness > changes. Add a function to update the value in the core, and > additionally send a uevent so that userspace can pop up appropriate > UI. The uevents are flagged depending on whether the update originated > in the kernel or from userspace, making it easier to only display UI > at the appropriate time. Ok. I have it working (event-based AND poll-based) in thinkpad-acpi, although it needs to be tested by dual-GPU, ACPI-based and OpRegion-based owners. Should the driver notify of *any* changes, even when the user is hitting the "ceiling" or the "floor" and the backlight value didn't really change? If the answer is no, shouldn't the backlight class filter these out itself, to guarantee a consistent experience? -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- 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/