From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [RFC PATCH 1/2] acpi: video: Allow forcing native backlight on non win8 machines Date: Tue, 10 Mar 2015 23:42:21 +0100 Message-ID: <54FF734D.5070107@redhat.com> References: <1425368350-4028-1-git-send-email-hdegoede@redhat.com> <54F5B300.7020904@redhat.com> <54F672EC.6010404@intel.com> <3175131.PO6aPjpaNK@vostro.rjw.lan> 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]:33863 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752893AbbCJWm1 (ORCPT ); Tue, 10 Mar 2015 18:42:27 -0400 In-Reply-To: <3175131.PO6aPjpaNK@vostro.rjw.lan> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" , Aaron Lu Cc: Zhang Rui , linux-acpi@vger.kernel.org Hi, On 03/10/2015 11:25 PM, Rafael J. Wysocki wrote: > On Wednesday, March 04, 2015 10:50:20 AM Aaron Lu wrote: >> On 03/03/2015 09:11 PM, Hans de Goede wrote: >>> Hi, >>> >>> On 03-03-15 09:26, Aaron Lu wrote: >>>> On 03/03/2015 03:39 PM, Hans de Goede wrote: >>>>> The native backlight behavior (so not registering both the acpi-video and the >>>>> vendor backlight driver) can be useful on some non win8 machines too, allow >>>>> the user to force this behavior by passing video.use_native_backlight=2 >>>>> on the kernel commandline. >>>> >>>> Just bikeshedding, what about doing it this way? >>>> >>>> In the acpi_video_use_native_backlight function: >>>> 1 If user has set a cmdline option, use that(no matter if it is a win8 >>>> system or not); >>>> 2 If the system is in a DMI table, use that(no matter if it is a win8 >>>> system or not); >>>> 3 return true if this is a win8 system; false otherwise. >>>> >>>> Something like this: >>> >>> That works for me, and has the added advantage of not changing the >>> cmdline syntax (but it does change the cmdline behavior ...). >> >> Oh yes, I didn't consider this. Not sure how much impact this will have, >> but I don't see an immediate problem with it, so let's see. >> >>> >>> So going either way is fine with me. >>> >>> Aaron's version is: >>> >>> Acked-by: Hans de Goede >> >> Thanks. Here is the full patch: >> >> From: Aaron Lu >> Date: Wed, 4 Mar 2015 10:24:58 +0800 >> Subject: [PATCH] acpi: video: Allow forcing native backlight on non win8 >> machines >> >> The native backlight behavior (so not registering both the acpi-video >> and the vendor backlight driver) can be useful on some non win8 machines >> too, so change the behavior of the video.use_native_backlight=1 or 0 >> kernel cmdline option to be: if user has set video.use_native_backlight=1 >> or 0, use that no matter if it is a win8 system or not. Also, we will >> put some known systems into the DMI table to make them either use native >> backlight interface or not, so the use_native_backlight_dmi is used to >> reflect that. >> >> Original-by: Hans de Goede >> Signed-offby: Aaron Lu >> Acked-by: Hans de Goede >> --- >> drivers/acpi/video.c | 9 +++++---- >> 1 file changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c >> index debd30917010..4cd0c8a4fd9d 100644 >> --- a/drivers/acpi/video.c >> +++ b/drivers/acpi/video.c >> @@ -84,7 +84,7 @@ module_param(allow_duplicates, bool, 0644); >> */ >> static int use_native_backlight_param = -1; >> module_param_named(use_native_backlight, use_native_backlight_param, int, 0444); >> -static bool use_native_backlight_dmi = true; >> +static int use_native_backlight_dmi = -1; > > So can we have proper symbols instead of these numbers, please? So you want to have a native_backlight enum or some such ? with -1 being not_set ? Regards, Hans > >> >> static int register_count; >> static struct mutex video_list_lock; >> @@ -239,13 +239,14 @@ static bool acpi_video_use_native_backlight(void) >> { >> if (use_native_backlight_param != -1) >> return use_native_backlight_param; >> - else >> + else if (use_native_backlight_dmi != -1) >> return use_native_backlight_dmi; >> + return acpi_osi_is_win8(); >> } >> >> bool acpi_video_verify_backlight_support(void) >> { >> - if (acpi_osi_is_win8() && acpi_video_use_native_backlight() && >> + if (acpi_video_use_native_backlight() && >> backlight_device_registered(BACKLIGHT_RAW)) >> return false; >> return acpi_video_backlight_support(); >> @@ -414,7 +415,7 @@ static int __init video_set_bqc_offset(const struct dmi_system_id *d) >> >> static int __init video_disable_native_backlight(const struct dmi_system_id *d) >> { >> - use_native_backlight_dmi = false; >> + use_native_backlight_dmi = 0; >> return 0; >> } >> >> >