From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751735AbaK2RfI (ORCPT ); Sat, 29 Nov 2014 12:35:08 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:44594 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751506AbaK2Re6 (ORCPT ); Sat, 29 Nov 2014 12:34:58 -0500 Date: Sat, 29 Nov 2014 09:34:47 -0800 From: Brian Norris To: Aaron Lu Cc: "Rafael J. Wysocki" , ntrrgc@gmail.com, ACPI Devel Mailing List , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ACPI / video: check _DOD list when creating backlight device Message-ID: <20141129173447.GA3608@norris-Latitude-E6410> References: <542A4949.2020208@intel.com> <1648939.GaN1bonAuX@vostro.rjw.lan> <5436470B.3030306@intel.com> <20141128095928.GA5106@norris-Latitude-E6410> <54786294.5030105@intel.com> <20141128171812.GA3658@norris-Latitude-E6410> <5479C3BB.5080905@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5479C3BB.5080905@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 29, 2014 at 09:01:47PM +0800, Aaron Lu wrote: > On 11/29/2014 01:18 AM, Brian Norris wrote: > > On Fri, Nov 28, 2014 at 07:55:00PM +0800, Aaron Lu wrote: > >> On 11/28/2014 05:59 PM, Brian Norris wrote: > >>> Do you need any additional info to handle the regression, or should we > >>> just revert the patch? > >> > >> Please attach acpidump, dmesg with video.dyndbg="module video +pft" in > >> kernel cmdline, list the /sys/class/backlight with and without this > >> commit, thanks. [...] > > Before reverting: > > > > $ ls -al /sys/class/backlight > > total 0 > > drwxr-xr-x 2 root root 0 Nov 28 09:01 . > > drwxr-xr-x 58 root root 0 Nov 28 09:01 .. > > > > After reverting: > > > > $ ls -al /sys/class/backlight > > total 0 > > drwxr-xr-x 2 root root 0 Nov 28 09:10 . > > drwxr-xr-x 50 root root 0 Nov 28 09:10 .. > > lrwxrwxrwx 1 root root 0 Nov 28 09:09 acpi_video0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 > > The current logic to bind device doesn't work with your system, that > logic is there for a long time so I prefer not to change that, instead, > I can change the newly added function acpi_video_device_in_dod to let it > directly compare the 0-12 bits of the ID to decide if the video output > device is in the _DOD list. Can you please try the following patch? > > diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c > index 41e6b977ceb2..185a57d13723 100644 > --- a/drivers/acpi/video.c > +++ b/drivers/acpi/video.c > @@ -1164,7 +1164,8 @@ static bool acpi_video_device_in_dod(struct acpi_video_device *device) > return true; > > for (i = 0; i < video->attached_count; i++) { > - if (video->attached_array[i].bind_info == device) > + if ((video->attached_array[i].value.int_val & 0xfff) == > + (device->device_id & 0xfff)) > return true; > } Thanks for the patch! This works better for me: $ ls -al /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 Nov 29 09:00 . drwxr-xr-x 50 root root 0 Nov 29 09:00 .. lrwxrwxrwx 1 root root 0 Nov 29 08:59 acpi_video0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 And I see no dmesg dev_dbg() prints from the acpi/video module. Tested-by: Brian Norris Should we try to get this into 3.18, then? Thanks, Brian