From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [Regression]: Changing brightness does not work with v3.16-rc4 Date: Wed, 16 Jul 2014 13:52:47 +0200 Message-ID: <53C6678F.90905@redhat.com> References: <20140712180636.698e2e4c@saldaea> <53C53543.1050207@redhat.com> <53C53E89.2020505@intel.com> <2231725.PEI454q0UP@vostro.rjw.lan> <53C61BD5.8080501@redhat.com> <53C6276A.6020206@intel.com> <53C63431.7020205@redhat.com> <53C63955.2090905@redhat.com> <20140716135035.21106dfe@saldaea> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:63521 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932684AbaGPLwy (ORCPT ); Wed, 16 Jul 2014 07:52:54 -0400 In-Reply-To: <20140716135035.21106dfe@saldaea> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Julian Wollrath Cc: Aaron Lu , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org Hi, On 07/16/2014 01:50 PM, Julian Wollrath wrote: > Am Wed, 16 Jul 2014 10:35:33 +0200 > schrieb Hans de Goede : > >> Hi, >> >> On 07/16/2014 10:13 AM, Hans de Goede wrote: >> >> >> >>> I realize that this does not fix Julian's problem. As I see it >>> there are 2 separate problems here: >>> >>> 1) backlight control issues on Windows 8 laptops, this is what we >>> are trying to solve with video.use_native_backlight=1 (and without >>> using any acpi_osi override) >>> >>> 2) Some component in the stack needs to responds to backlight >>> key-presses and actually use the backlight control to change the >>> backlight setting, normally this is done by gnome / kde / unity / >>> xfce, but what about users not running those? For some of those >>> users brightness_switch_enabled=1 has been making things work for >>> them, but that only works if acpi-video controls the backlight, >>> which it does not do everywhere, and which we want to get away from >>> for Windows 8 laptops since it is just too broken there. >>> >>> Note that 2. is not limited to Windows 8 laptops / acpi-video in any >>> way, we've 23 non acpi-video backlight drivers under >>> drivers/platform/x86/ alone + the native gpu backlight drivers. So >>> what we really need is a solution for any laptop not using >>> acpi-video for backlight control and not running one of the big 4 >>> desktop environments. >>> >>> Note that we pretty much have the same problem for any acpi event, >>> power button pressed, lid closed, etc. are all "key press" type >>> events typically handles by the desktop enviroment (e.g. we don't >>> automatically suspend on lid-close, we just tell userspace). And we >>> already have a solution for these type of events when running a >>> desktop environment which handles them, these get handled by acpid. >>> So to me it seems that >> >> s/handles/does not handle/ small but important typo. >> >>> the obvious (and one and only right) way to fix this is to teach >>> acpid to deal with brightness key-presses. >>> >>> I'm willing to write a patch for acpid to implement this, and then >>> Julian's setup should just work without needing any special kernel >>> commandline options. >>> >>> Julian would that be an acceptable solution for you, and would you >>> be willing to test such a patch ? > Yes, of course that would be an acceptable solution for me and yes, I > would be willing to test such a patch. Ok, great. I've putten this (pretty high) on my todo list, I'll let you know when I've something ready to test. Regards, Hans