From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhang Rui Subject: Re: Check for ACPI backlight support otherwise use vendor ACPI Date: Thu, 31 Jul 2008 13:22:51 +0800 Message-ID: <1217481771.2969.75.camel@rzhang-dt> References: <200807310251.m6V2pXDe027356@turbo.physics.adelaide.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga11.intel.com ([192.55.52.93]:35504 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752001AbYGaFZF (ORCPT ); Thu, 31 Jul 2008 01:25:05 -0400 In-Reply-To: <200807310251.m6V2pXDe027356@turbo.physics.adelaide.edu.au> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Jonathan Woithe Cc: Thomas Renninger , Yves-Alexis Perez , ak@linux.intel.com, mjg59@srcf.ucam.org, hmh@hmh.eng.br, corentincj@iksaif.net, linux-acpi@vger.kernel.org, dannybaumann@web.de, marcus@better.se, mzxreary@0pointer.de, carlos@strangeworlds.co.uk, malattia@linux.it, nokos@gmx.net On Thu, 2008-07-31 at 10:51 +0800, Jonathan Woithe wrote: > > > I'm trying to sort out the status of this myself. Is the > expectation > > > that your patches *with* the IGD work from Matthew/Hong should > mean that > > > Fujitsus implementing IGD should not need fujitsu-laptop in order > to > > > provide working software backlight brightness control? > > I think so. >=20 > Ok. >=20 > > > Or shouldn't Matthew/Hong's patchset be necessary with your patch > in > > > theory? > > Thomas' patch assigns the responsibility to acpi video driver or > > platform drivers when a laptop supports brightness/display switch > both > > via ACPI video extension and vendor specific control methods. > > > > brightness/display switch via ACPI video driver sometimes doesn't > work > > even if the ACPI control methods are available, and Matthew/Hong's > patch > > fixes this problem, on platforms with intel integrated graphics > cards. >=20 > I see. >=20 > > And now, we should root cause why acpi_video_backlight_support() > failed > > on this laptop. >=20 > Agreed. >=20 > > > so allowing fujitsu-laptop to co-exist with video.ko handling the > > > backlight (as your patches allow) is the right thing to do. > > > > sure, they will co-exist, but I don't think fujitsu-laptop should > handle > > the backlight stuff, unless it's explicitly stated via the boot > > parameter "=C3=AF=C2=BB=C2=BFacpi_backlight=3Dvendor". >=20 > For laptops with both ACPI video extensions and vendor specific > control > methods I agree with this. However, users of laptops which have only > vendor > specific control methods (of which the S7020 is one AFAIK) should not > have > to give any boot parameters for things to work for them. sure. In this case, =EF=BB=BFacpi_video_backlight_support() returns false, and vendor driver will handle the backlight switching. > In other words, > "acpi_backlight=3Dvendor" should only come into play when the machine > has the > ACPI video extensions. I am assuming that this is the intention sinc= e > that's what the current patches appear to do. Yes. >=20 > Is there a canonical source for Matthew/Hong's patch? To totally wra= p > this > up I would like to try the S7020 with Matthew/Hong+Thomas. > I doubt > Matthew/Hong's work is relevant to the S7020 given that it's 3+ years > old > now, but it's best to test these things early. Agree. I think Matthew/Hong's patch should have no effect on your laptops, and fujistu-laptop should handle the backlight switch as before. thanks, rui -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html