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

Rafael J. Wysocki
2013-07-16T21:51:29Z

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?

Rafael

> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> index 01b1a25..71865f7 100644
> --- a/drivers/acpi/video.c
> +++ b/drivers/acpi/video.c
> @@ -900,6 +900,9 @@ static void acpi_video_device_find_cap(struct
> acpi_video_device *device)
> device->cap._DDC = 1;
> }
>
> + if (acpi_video_init_brightness(device))
> + return;
> +
> if (acpi_video_verify_backlight_support()) {
> struct backlight_properties props;
> struct pci_dev *pdev;
> @@ -909,9 +912,6 @@ static void acpi_video_device_find_cap(struct
> acpi_video_device *device)
> static int count = 0;
> char *name;
>
> - result = acpi_video_init_brightness(device);
> - if (result)
> - return;
> name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
> if (!name)
> return;
>
>
> --
> Matthew Garrett | mjg59@srcf.ucam.org
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.