[PATCH 5/5] ACPI: Tie ACPI backlight devices to PCI devices if possible

[Matthew Garrett]

On Mon, Feb 07, 2011 at 02:32:35PM -0700, Bjorn Helgaas wrote:

> I'm not familiar with video devices, but I agree, this situation does
> feel broken.  Is it the case that there's a PCI device as well as an
> ACPI namespace Device for the same piece of hardware?  If so, I assume
> the reason for the ACPI Device is to have a "standard" interface to
> a platform knob like backlight control.
> 
> In that case, it seems like we should rely on PCI for enumeration and
> driver binding, have some sort of hook the PCI driver could use to
> twiddle that knob (using the ACPI methods), and make the ACPI Device
> ineligible for driver binding.  In other words, it sounds like part
> of the problem is that we have two drivers binding to what's really
> a single piece of hardware.

Part of the problem is that ACPI video devices aren't inherently PCI 
devices.

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