Comment 205 for bug 1098216

(In reply to comment #77)
> Unfortunately, just setting acpi_backlight=vendor has too many side effects
> to
> completely solve the problem:
> 1. It causes _BCL not to be called, so the firmware won't generate ACPI
> events
> for the keypresses. Instead, the firmware will handle them entirely
> internally,
> changing the brightness. (See [1])

Is it possible for thinkpad-acpi module to control this behaviour? I mean, on hotkey press, do not handle backlight internally, just send out event.

> 2. thinkpad_acpi will not mask the brightness keys, so we get hotkey events
> through that, in addition to the firmware's internal brightness changes.

I don't see anywhere backlight gets changed internally. Is it done by some HKEY function?

> 3. thinkpad_acpi creates its "thinkpad_screen" sysfs device, which userspace
> prefers to the intel_backlight device that we want to be using.

Does that interface work or not?
Thanks.