[Intel-gfx] Prepare for 2.3.2

[Lukas Hejtmanek]

On Fri, Jun 13, 2008 at 09:12:06AM -0700, Jesse Barnes wrote:
> Did you try what I suggested in response your last patch?  I thought Zhenyu 
> would push that, but I guess the code hasn't changed for awhile.

Not sure what do you mean.

> > @@ -1081,7 +1090,10 @@ i830_lvds_set_property(xf86OutputPtr output, Atom
> > property, "RRConfigureOutputProperty error, %d\n", ret); }
> >         /* Set the current value of the backlight property */
> > -       data = dev_priv->get_backlight(output);
> > +       if ((INREG(PP_CONTROL)&POWER_TARGET_ON) && dev_priv->dpmsoff == 0)
> > +          data = dev_priv->get_backlight(output);
> > +       else
> > +          data = dev_priv->backlight_duty_cycle;
> >         ret = RRChangeOutputProperty(output->randr_output, backlight_atom,
> >                                      XA_INTEGER, 32, PropModeReplace, 1,
> > &data, FALSE, TRUE);
> > @@ -1140,8 +1152,12 @@ i830_lvds_get_property(xf86OutputPtr output, Atom
> > property) */
> >      if (property == backlight_atom) {
> >         int val;
> > -       val = dev_priv->get_backlight(output);
> > -       dev_priv->backlight_duty_cycle = val;
> > +       if ((INREG(PP_CONTROL)&POWER_TARGET_ON) && dev_priv->dpmsoff == 0)
> > +               val = dev_priv->get_backlight(output);
> > +               dev_priv->backlight_duty_cycle = val;
> > +       } else {
> > +               val = dev_priv->backlight_duty_cycle;
> > +       }
> >         ret = RRChangeOutputProperty(output->randr_output, backlight_atom,
> >                                      XA_INTEGER, 32, PropModeReplace, 1,
> > &val, FALSE, TRUE);
> 
> These changes are to avoid returning a 0 backlight brightness when the LCD is 
> off?  Or did you find cases where the value wasn't 0 even though the display 
> was supposed to be off?

Well, it happened that my Xserver started with the maximum backlight value.
I wondered why this happens. I found that it is because the backlight value is
set to 0 somewhere in to code path during Xserver startup. Thereafter,
SetDPMSOn kicks the maximum backlight value.

So I investigated why I got backlight value to 0. And it was because there is
called DPMS Off during startup and while being off, randr gets initialized and
it calls lvds_set or lvds_get property (not sure which one) and it reads the
current backlight value and save it. However, the value is 0 as DPMS if OFF
now. I wonder why this happens now and not before. But it definitely happens.

-- 
Lukáš Hejtmánek