[Update][PATCH] ACPI / video / i915: Remove ACPI backlight if firmware expects Windows 8

[Igor Gnatenko]

On Wed, 2013-07-17 at 13:38 +0200, Rafael J. Wysocki wrote:
> On Wednesday, July 17, 2013 09:16:38 AM Igor Gnatenko wrote:
> > On Wed, 2013-07-17 at 00:01 +0200, Rafael J. Wysocki wrote:
> > > On Tuesday, July 16, 2013 05:08:16 PM Matthew Garrett wrote:
> > > > On Tue, 2013-07-16 at 17:32 +0400, Igor Gnatenko wrote:
> > > > > Hmm. I found regression in user-space. In GNOME (maybe and other DEs) we no longer see switch status of backlight.
> > > > 
> > > > Yeah, I can duplicate that. Rafael, we have to call
> > > > acpi_video_init_brightness() even if we're not going to initialise the
> > > > backlight - Thinkpads seem to use this as the trigger for enabling ACPI
> > > > notifications rather than handling it in firmware. This seems to do the
> > > > job:
> > > 
> > > Igor, does this additional patch from Matthew help?
> > Yes. With this patch I have backlight switch indicator on my ThinkPad X230.
> 
> OK, thanks for the confirmation.
> 
> Can you please also check if applying the appended patch on top of the Matthew's
> one changes anything (ie. things still work)?
Yes. I've tested and not found regressions in indicator or in switcher. Good work.
> 
> Rafael
> 
> 
> ---
Tested-by: Igor Gnatenko <i.gnatenko.brain at gmail.com>
>  drivers/acpi/video.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> Index: linux-pm/drivers/acpi/video.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/video.c
> +++ linux-pm/drivers/acpi/video.c
> @@ -957,6 +957,11 @@ static void acpi_video_device_find_cap(s
>  		if (result)
>  			printk(KERN_ERR PREFIX "Create sysfs link\n");
>  
> +	} else {
> +		/* Remove the brightness object. */
> +		kfree(device->brightness->levels);
> +		kfree(device->brightness);
> +		device->brightness = NULL;
>  	}
>  }
>  
> 
> 
-- 
Igor Gnatenko
Fedora release 19 (Schrödinger’s Cat)
Linux 3.11.0-0.rc0.git7.1.fc20.x86_64