Re: [PATCH update] acpi: video: Allow forcing native backlight on non win8, machines

[Aaron Lu <aaron.lu@intel.com>]

On Wed, Mar 11, 2015 at 12:14:41PM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11-03-15 07:14, Aaron Lu wrote:
> >On 03/11/2015 07:10 AM, Rafael J. Wysocki wrote:
> >>On Tuesday, March 10, 2015 11:42:21 PM Hans de Goede wrote:
> >>>So you want to have a native_backlight enum or some such ? with -1 being not_set ?
> >>
> >>Yes, something like that.
> >
> >OK, here is an updated one:
> 
> Looks good to me, my ack still stands. I need to send a bunch of
> mails back / forth to tackle the issue the ideapad which caused me to
> work on this in the first case. So lets merge this one first, and
> then I'll get back with a patch on top of this when I know how to
> actually best deal with the problem on that machine.

Thanks for the ack and taking care of the problem.

Regards,
Aaron

> 
> Regards,
> 
> Hans
> 
> 
> >
> > From db4eb1928219e47fcfbffb913f08b1e1b432c28a Mon Sep 17 00:00:00 2001
> >From: Aaron Lu <aaron.lu@intel.com>
> >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, and the use_native_backlight_dmi is used to
> >reflect that.
> >
> >Original-by: Hans de Goede <hdegoede@redhat.com>
> >Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> >Acked-by: Hans de Goede <hdegoede@redhat.com>
> >---
> >  drivers/acpi/video.c | 19 +++++++++++++------
> >  1 file changed, 13 insertions(+), 6 deletions(-)
> >
> >diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> >index 26eb70c8f518..2f45dca31724 100644
> >--- a/drivers/acpi/video.c
> >+++ b/drivers/acpi/video.c
> >@@ -82,9 +82,15 @@ module_param(allow_duplicates, bool, 0644);
> >   * For Windows 8 systems: used to decide if video module
> >   * should skip registering backlight interface of its own.
> >   */
> >-static int use_native_backlight_param = -1;
> >+enum {
> >+	NATIVE_BACKLIGHT_NOT_SET = -1,
> >+	NATIVE_BACKLIGHT_OFF,
> >+	NATIVE_BACKLIGHT_ON,
> >+};
> >+
> >+static int use_native_backlight_param = NATIVE_BACKLIGHT_NOT_SET;
> >  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 = NATIVE_BACKLIGHT_NOT_SET;
> >
> >  static int register_count;
> >  static struct mutex video_list_lock;
> >@@ -237,15 +243,16 @@ static void acpi_video_switch_brightness(struct work_struct *work);
> >
> >  static bool acpi_video_use_native_backlight(void)
> >  {
> >-	if (use_native_backlight_param != -1)
> >+	if (use_native_backlight_param != NATIVE_BACKLIGHT_NOT_SET)
> >  		return use_native_backlight_param;
> >-	else
> >+	else if (use_native_backlight_dmi != NATIVE_BACKLIGHT_NOT_SET)
> >  		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 +421,7 @@ 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 = NATIVE_BACKLIGHT_OFF;
> >  	return 0;
> >  }
> >
> >