Re: ACPI_VIDEO and BACKLIGHT_CLASS_DEVICE

Matthew Garrett
2010-11-12T03:46:22Z

On Thu, Nov 11, 2010 at 10:00:03PM -0500, Alan Stern wrote:

> But my computer doesn't have an LCD display. It's a desktop, not a
> laptop. So why do I need BACKLIGHT_CLASS_DEVICE to be enabled?

Well, in the near future ddc-ci will be hooked up and you'll have
backlight control over VGA if your monitor supports it, so even if we
fix this up now you'll just end up getting it back in the near future
because we can't tell that at build-time...

> Are you saying I don't need ACPI_VIDEO if the machine doesn't have an
> integrated LCD display? That doesn't agree with the Kconfig help
> message.

But to that, yes. The only reason to use ACPI_VIDEO is to get EDID from
firmware (which isn't relevant on desktops) or to control backlights.
Every other theoretical feature it has is useless in the real world.

--
Matthew Garrett | mjg59@srcf.ucam.org