[ltp] X61 Brightness Question

[Hendrik-Jan Heins]

2007/8/15, Henrique de Moraes Holschuh <hmh@hmh.eng.br>:
> On Wed, 15 Aug 2007, Hendrik-Jan Heins wrote:
> > I just now redid everything with 0.15.
> > Unfortunatly, I see no difference in effects, except for the fact that
> > I now NEED the video module to get brightness working
>
> Eh?  It shouldn't have made any difference on that regard.  Are you sure
> thinkpad-acpi was the only thing that changed?
>
Yup, I actually just copied that module from the source tree (after
compiling of course)

> > > The new thinkpads are moving to generic ACPI video handling, and that's the
> > > ACPI video driver's business.
> > Yup, I'm seeing that now.
>
> You were doing so before...
>
Yes, but before I saw in acpi_listen that with brightness down
actually ywo events were registered, one IBM hotkey and one video
Now I only see the video event on both keys.

> > The brightness_mode=2 option doesn't seem to do much. I tried it with
> > and without, but I saw no difference.
>
> If you leave it out but start the driver with the debug=0xffff parameter,
> you'll see it selects brightness_mode=2 for you.  The old way might or might
> not work well on your thinkpad, it was removed because it was changing an EC
> register that was not used anymore, so we better not touch it.
>
> And it certainly wouldn't work right when reading brightness if you used
> anything but thinkpad-acpi to change it.
>
Well, in dmesg it actually says it recognises an X61 and my bios
revison, so I think that works?


> > Actually now I do see 0-7 brightness levels in
> > /sys/class/backlight/thinkpad_screen/actual_brightness
> > Shouldn't I see more levels?
>
> Yes, but I didn't figure out how to detect a 16-level thinkpad yet from the
> ACPI tables.
>
Maybe you shouldn't try to detect it, but set it. Apparently it is
known how many levels there are for each type of thinkpad?

> > The scripts I'm using to set brightness:
> ...
>
> You just did in userspace what the acpi video module does in kernel space,
> but using thinkpad-acpi instead of the generic ACPI backlight level methods
> to change the brightness.
>
Right.. But I cannot get that to work with the kernel modules!
Without my scripts, IU simply have no brightness control through the keys.
What modules do I need for this; as in: what am I missing here?

> That's why it was working before :p
>
Probably

Hendrik-Jan