Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751790AbaK2NCD (ORCPT ); Sat, 29 Nov 2014 08:02:03 -0500 Received: from mga11.intel.com ([192.55.52.93]:51119 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583AbaK2NCC (ORCPT ); Sat, 29 Nov 2014 08:02:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,483,1413270000"; d="scan'208";a="639918250" Message-ID: <5479C3BB.5080905@intel.com> Date: Sat, 29 Nov 2014 21:01:47 +0800 From: Aaron Lu MIME-Version: 1.0 To: Brian Norris 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 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> In-Reply-To: <20141128171812.GA3658@norris-Latitude-E6410> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: >>> And indeed, there is a regression! My Dell Latituded E6410's backlight >>> control no longer works after this commit, and I get messages like this >>> instead: >>> >>> [ 57.214610] ACPI: Failed to switch the brightness >>> >>> If I revert this commit, my backlight controls work again. Also, I >>> regain a cooling device (?) that was being ignored: >>> >>> [ 1.332682] acpi device:02: registered as cooling_device0 >>> >>> 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. > > Appending dmesg and attaching acpidump. Unfortunately, I'm using a few > binary modules, since Wifi and GPU suspend/resume support are broken > otherwise, but I did test briefly with Nouveau anyway. Results are > essentially the same with Nouveau (although Nouveau seems to provide an > extra backlight device, though it doesn't seem to do anything for me). > > 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, Aaron -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/