Re: [gpm] Support for brightness_in_hardware hal property

[Tomaž Šolc <tomaz solc tablix org>]

Hi

> I should be a lot faster to set with XRANDR - is that what you found
> also?

I haven't noticed any difference in speed.

> > If I force the use of HAL in gpm_brightness_init(), the brightness
> > buttons work properly, but the feedback widget doesn't appear on the
> > screen.
>
> Right, I guess the gpm_brightness_xrandr_X commands are not setting
> hw_changed properly.

I thought widget is displayed when the "brightness-changed" signal is 
emited (like in gpm_brightness_xrandr_may_have_changed() ).

I don't see any function that would emit this signal in 
gpm_brightness_hal_*.

> > I'm not sure what is the correct way to solve this problem. If xrandr is
> > now the preferred way, what is the best way to tell it that brightness
> > buttons work in hardware?
>
> Well, there are two ways -- preferable would be to keep track of the
> last brightness and then compare the current against the last, or we
> could use the hal attribute in the xrandr code. I'm not sure which is
> the best to do.

Hm. It looks like gpm_brightness_xrandr_output_get_internal() doesn't 
detect that the hardware has changed the brightness.

If I disable gpm_brightness_xrandr_output_set_internal(), then 
output_get always returns the same value, regardless of the actual state 
of the backlight.

So even if you use hal attribute, you can't get the real brightness 
level through xrandr.

There is an added complication that on Eee you can't know which 
brightness button was pressed (up or down - on mine both buttons behave 
as BrightnessDown). I heard that some other Asus laptops also behave 
like this.

Best regards
Tomaz