From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Purdie Subject: Re: [PATCH] backlight: do not power off backlight when unregistering (try 2) Date: Fri, 10 Nov 2006 10:44:40 +0000 Message-ID: <1163155480.5550.0.camel@localhost.localdomain> References: <20061105225429.GE14295@khazad-dum.debian.net> <1162773394.5473.18.camel@localhost.localdomain> <20061110000829.GA9021@khazad-dum.debian.net> <20061110003237.GB9021@khazad-dum.debian.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from tim.rpsys.net ([194.106.48.114]:35768 "EHLO tim.rpsys.net") by vger.kernel.org with ESMTP id S1946390AbWKJKp6 (ORCPT ); Fri, 10 Nov 2006 05:45:58 -0500 In-Reply-To: <20061110003237.GB9021@khazad-dum.debian.net> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Henrique de Moraes Holschuh Cc: benh@kernel.crashing.org, paulus@samba.org, Lennart Poettering , Andriy Skulysh , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Antonino Daplas , Holger Macht On Thu, 2006-11-09 at 22:32 -0200, Henrique de Moraes Holschuh wrote: > ACPI drivers like ibm-acpi are moving to the backlight sysfs infrastructure. > During ibm-acpi testing, I have noticed that backlight_device_unregister() > sets the display brightness and power to zero. > > This causes the display to be dimmed on ibm-acpi module removal. It will > affect all other ACPI drivers that are being converted to use the backlight > class, as well. It also affects a number of framebuffer devices that are > used on desktops and laptops which might also not want such behaviour. > > Since working around this behaviour requires undesireable hacks, Richard > Purdie decided that we would be better off reverting the changes in the > sysfs class, and adding the code to dim and power off the backlight device > to the drivers that want it. This patch is my attempt to do so. > > Patch against latest linux-2.6.git. Changes untested, as I lack the > required hardware. Still, they are trivial enough that, apart from typos, > there is little chance of getting them wrong. > > Signed-off-by: Henrique de Moraes Holschuh > Cc: Richard Purdie > Cc: Andriy Skulysh > Cc: Antonino Daplas Acked-by: Richard Purdie