From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Backlight control broken on Lenovo Ideapad Z570 Date: Wed, 18 Mar 2015 14:12:06 +0100 Message-ID: <550979A6.20306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35438 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755962AbbCRNMJ (ORCPT ); Wed, 18 Mar 2015 09:12:09 -0400 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Stepan Bujnak Cc: be.0@gmx.com, linux-acpi Hi Stepan, I'm mailing you because you are the author of: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a11d342f I've been debugging the same problem together with a Fedora user: https://bugzilla.redhat.com/show_bug.cgi?id=1187004 And for him your fix does not work, before your fix landed we already came to the conclusion that to fix this we need to disable both the acpi_video backlight interface as well as the ideapad-laptop interface. Your patch only disables the acpi_video backlight interface (and as a side effect actually enables the ideapad-laptop interface). I assume that you've a working backlight setup on your Lenovo Ideapad Z570, can you please do: ls /sys/class/backlight And let us know which interfaces show up there. Either you do have a working ideapad_laptop interface, or you only get intel_backlight and for some reason ideapad_laptop is not loading on your system (not enabled in your kernel config, or blacklisted?). If you only have intel_backlight then that explains why things are not working for Be (the author of the Fedora bugreport), if you do have an ideapad_laptop interface and that does work for you, then it seems that not all Lenovo Ideapad Z570-s are created equal. In that case can you please blacklist the ideapad-laptop module, reboot and see if things still work for you when using intel_backlight to control the backlight? Once we've a confirmation that either you are already using intel_backlight, or that intel_backlight also works on your Ideapad, then I'll write a patch to replace yours which leaves only intel_backlight even if the ideapad-laptop driver gets loaded. Thanks & Regards, Hans