From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH 2/2] ACPI Check for backlight support via ACPI video.ko otherwise use vendor ACPI drivers Date: Thu, 10 Jul 2008 11:07:09 +0100 Message-ID: <20080710100709.GA5017@srcf.ucam.org> References: <200807031809.03172.trenn@suse.de> <200807091649.52605.trenn@suse.de> <20080709145758.GA22147@srcf.ucam.org> <200807091800.27608.trenn@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200807091800.27608.trenn@suse.de> Sender: linux-acpi-owner@vger.kernel.org To: Thomas Renninger Cc: ak@linux.intel.com, linux-acpi@vger.kernel.org, Henrique de Moraes Holschuh , Carlos Corbacho , Jonathan Woithe , malattia@linux.it, stelian@popies.net, linux-next@vger.kernel.org, Corentin CHARY , Lennart Poettering , Julia Jomantaite , corsac@debian.org, dannybaumann@web.de, marcus@better.se, Zhang Rui , Hong Liu List-Id: linux-next.vger.kernel.org On Wed, Jul 09, 2008 at 06:00:23PM +0200, Thomas Renninger wrote: > ... > > For this to work, the ACPI video driver needs to work as it currently > > does. It is not correct for it to disable itself on IGD systems. > Right, now I got it. It is only the T61/Lenovo you must have the opregion > driver ready or you better fallback to thinkpad_acpi... > Is that correct? > I will add a dmi check for Lenovo in video_detect.c. > That would be: > - If ACPI Appendix B video brightness functions are found > | -> use video.ko > | | > | -> If it's a ThinkPad, check for Opregion BIOS support > | -> Use video.ko if IGD parts are implemented (and the one > | | ThinkPad specific func you had the 750ms delay is available) > | -> otherwise go back to thinkpad_acpi This is unnecessary logic. Let's just follow the spec. There's no need to use thinkpad_acpi here. > Please also provide an OSI string with your video opregion code parts, so that > BIOS can check whether the kernel is capable of serving IGD devices. Just > choose a random string you like, e.g. let OSI("Opregion Video Support") > return true. No. The DRM can be (and usually is) built as a module and OSI strings are going to be checked at ACPI init time. This can't be made to work correctly. Vendors can choose whether to use the opregion or old-style support based on whether the driver has enabled the support. -- Matthew Garrett | mjg59@srcf.ucam.org