On Wed, 2012-03-21 at 11:00 +0800, joeyli wrote:
> 於 三，2012-03-21 於 00:25 +0530，Pradeep Subrahmanion 提到：
> > > >From 5da43d2ee6c87dcf17fda34f0b50fe11b04a16bf Mon Sep 17 00:00:00 2001
> > > From: "Lee, Chun-Yi" <jlee@suse.com>
> > > Date: Tue, 20 Mar 2012 19:00:58 +0800
> > > Subject: [PATCH] acer-wmi: add quirk table for video backlight vendor mode
> > > 
> > > There have some acer laptop have broken _BCM implemenation, the AML
> > > code wrote value to EC register but firmware didn't change brighenss.
> > > 
> > > Fortunately, the brightness control works on those machines with
> > > vendor mode. So, add quirk table for video backlight vendor mode
> > > and unregister acpi video interface on those machines.
> > > 
> > > Tested on Acer TravelMate 4750
> > > 
> > > Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
> > > ---
> > >  drivers/platform/x86/Kconfig    |    4 ++++
> > >  drivers/platform/x86/acer-wmi.c |   38 +++++++++++++++++++++++++++++++++++---
> > >  2 files changed, 39 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > > index 15dbd8c..fe3a494 100644
> > > --- a/drivers/platform/x86/Kconfig
> > > +++ b/drivers/platform/x86/Kconfig
> > > @@ -26,6 +26,10 @@ config ACER_WMI
> > >  	depends on RFKILL || RFKILL = n
> > >  	depends on ACPI_WMI
> > >  	select INPUT_SPARSEKMAP
> > > +	# Acer WMI depends on ACPI_VIDEO when ACPI is enabled
> > > +	# but for select to work, need to select ACPI_VIDEO's dependencies, ick
> > > +        select VIDEO_OUTPUT_CONTROL if ACPI
> > > +        select ACPI_VIDEO if ACPI
> > >  	---help---
> > >  	  This is a driver for newer Acer (and Wistron) laptops. It adds
> > >  	  wireless radio and bluetooth control, and on some laptops,
> > > diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
> > > index 1e5290b..984a7b5 100644
> > > --- a/drivers/platform/x86/acer-wmi.c
> > > +++ b/drivers/platform/x86/acer-wmi.c
> > > @@ -43,6 +43,7 @@
> > >  #include <linux/input/sparse-keymap.h>
> > >  
> > >  #include <acpi/acpi_drivers.h>
> > > +#include <acpi/video.h>
> > >  
> > >  MODULE_AUTHOR("Carlos Corbacho");
> > >  MODULE_DESCRIPTION("Acer Laptop WMI Extras Driver");
> > > @@ -478,6 +479,33 @@ static struct dmi_system_id acer_quirks[] = {
> > >  	{}
> > >  };
> > >  
> > > +static int video_set_backlight_video_vendor(const struct dmi_system_id *d)
> > > +{
> > > +	interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > +	pr_info("Brightness must be controlled by generic video driver\n");
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct dmi_system_id video_vendor_dmi_table[] = {
> > > +	{
> > > +		.callback = video_set_backlight_video_vendor,
> > > +		.ident = "Acer Aspire 4736",
> > > +		.matches = {
> > > +			DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
> > > +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4736"),
> > > +		},
> > > +	},
> > > +	{
> > > +		.callback = video_set_backlight_video_vendor,
> > > +		.ident = "Acer TravelMate 4750",
> > > +		.matches = {
> > > +			DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
> > > +			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
> > > +		},
> > > +	},
> > > +	{}
> > > +};
> > > +
> > >  /* Find which quirks are needed for a particular vendor/ model pair */
> > >  static void find_quirks(void)
> > >  {
> > > @@ -1981,9 +2009,13 @@ static int __init acer_wmi_init(void)
> > >  	set_quirks();
> > >  
> > >  	if (acpi_video_backlight_support()) {
> > > -		interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > -		pr_info("Brightness must be controlled by "
> > > -		       "generic video driver\n");
> > > +		if (dmi_check_system(video_vendor_dmi_table)) {
> > > +			acpi_video_unregister();
> > > +		} else {
> > > +			interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > +			pr_info("Brightness must be controlled by "
> > > +				"acpi video driver\n");
> > > +		}
> > >  	}
> > >  
> > >  	if (wmi_has_guid(WMID_GUID3)) {
> > 
> > I tried out applied your patch . Boot message shows , 
> > 
> > [11.220410] acer_wmi: Brightness must be controlled by generic video
> > driver
> > 
> > Now 'acpi_video0' and 'intel_backlight' are present
> > inside /sys/class/backlight .Hot key works like earlier ( ie problem
> > after maximum level still exists).
> > I tried following commands , 
> > 
> 
> It's not the expected behavior.
> 
> This new patch should remove acpi_video0 interface on your machine.
> Please kindly provide your dmidecode:
>  dmidecode > dmidecode.log
>
> And, 
> please make should the patch really applied, you can do a bit change on
> pr_info message by yourself.

   Sorry . I think there was some mistake . I tried the patch again. Now
I see only intel_backlight inside /sys/class/backlight. There is no
acer-wmi interface . Is this the expected behavior ? . Or am I missing
anything ?



> 
> > echo 5 > /sys/class/backlight/acpi_video0/brightness 
> > echo 5 > /sys/class/backlight/intel_backlight/brightness
> > 
> > But it doesn't make any change . 
> > 
> > In my case  , 'acpi_backlight = vendor' does not make any difference since the hot key control 
> > 
> > already starts working with 'acpi_osi=Linux' option.
> > 
> > cat /proc/cmdline gives , 
> > 
> > BOOT_IMAGE=/boot/vmlinuz-3.3.0+
> > root=UUID=f0197a59-c067-4fd8-ad90-c4d721816077 ro acpi_osi=Linux 
> > 
> > 
> > Thanks , 
> > 
> > Pradeep Subrahmanion
> > 
> 
> OK, that's more clearly, please remove acpi_osi=Linux then re-test, I
> think the hotkey of backlight control only works with acpi_osi=Linux ?
> 
> 
> Thanks a lot!
> Joey Lee
> 
> 

Thanks , 

Pradeep Subrahmanion