Subject: Re: [PATCH 2/2] ACPI Check for backlight support via ACPI video.ko otherwise use vendor ACPI drivers

From: Matthew Garrett <[email-masked]>
Date: Thu, 3 Jul 2008 17:21:52 +0100

On Thu, Jul 03, 2008 at 06:08:59PM +0200, Thomas Renninger wrote:

> +	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "DRDY", &h_dummy))) {
> +		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IGD device\n"));
> +		video_caps |= ACPI_VIDEO_IGD;
> +	}

In principle, it's possible for a vendor to implement opregion but not 
actually use it until the tche flags are set. If anyone's done that then 
you've just broken backlight control on their system.

-- 
Matthew Garrett | [email-masked]