Re: [PATCH 3/4] ACPI: thinkpad-acpi: disable backlight handler if ACPI generic could do it

[Thomas Renninger <trenn@suse.de>]

On Tue, 2007-10-09 at 14:34 +0100, Matthew Garrett wrote:
> On Tue, Oct 09, 2007 at 03:29:12PM +0200, Thomas Renninger wrote:
> > static const struct acpi_device_id dummy_vid_device_ids[] = {
> > 	{"LNXVIDEO", 0},
> > 	{"", 0},
> > };
> 
> No. This will match if any of the video extension is implemented. We 
> only want it to match if backlight control is implemented. There are 
> plenty of Thinkpads that implement a subset of the video extension but 
> still need backlight control to be handled via the Thinkpad-specific 
> routes.
Yep, I just realized that :(
Maybe all required funcs (_BCM,_BCL,...) should get checked, but must
not be invoked or I am pretty sure brightness switch through buttons
won't work because the notify handler isn't used.

I wonder how we should make the video module not load then in a sane way
on those, udev rules in userspace would be very dirty..., dmiscan for
ThinkPad in scan.c and only set LNXVIDEO if _BCM,_BCL... are there also,
maybe the latter is acceptable?

   Thomas