On Thu, 6 Jan 2011 21:55:23 +0100, Alex Riesen <raa.lkml@gmail.com> wrote:
> On Thu, Jan 6, 2011 at 18:49, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> >
> > My fear is that some machines have a dependency between the backlight
> > and panel power status. The patch in question changed the timing between
> > turning on the panel and adjusting the backlight which would be restore
> > with:
> >
> > diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
> > index aa23070..0b40b4f 100644
> > --- a/drivers/gpu/drm/i915/intel_lvds.c
> > +++ b/drivers/gpu/drm/i915/intel_lvds.c
> > @@ -106,6 +106,12 @@ static void intel_lvds_enable(struct intel_lvds *intel_lvds)
> >        I915_WRITE(ctl_reg, I915_READ(ctl_reg) | POWER_TARGET_ON);
> >        POSTING_READ(lvds_reg);
> >
> > +       {
> > +               u32 reg = HAS_PCH_SPLIT(dev) ? PCH_PP_STATUS : PPS_STATUS;
> > +               if (wait_for(I915_READ(reg) & PP_ON, 1000))
> > +                       DRM_ERROR("timed out waiting for panel to power up\n");
> > +       }
> > +
> >        intel_panel_set_backlight(dev, dev_priv->backlight_level);
> >  }
> 
> FWIW it does not compile:
>   CC      drivers/gpu/drm/i915/intel_lvds.o
> drivers/gpu/drm/i915/intel_lvds.c: In function ‘intel_lvds_enable’:
> drivers/gpu/drm/i915/intel_lvds.c:110: error: ‘PPS_STATUS’ undeclared
> (first use in this function)
> drivers/gpu/drm/i915/intel_lvds.c:110: error: (Each undeclared
> identifier is reported only once
> drivers/gpu/drm/i915/intel_lvds.c:110: error: for each function it appears in.)
> make[4]: *** [drivers/gpu/drm/i915/intel_lvds.o] Error 1

Daniel quickly pointed out my typo: s/PPS_STATUS/PP_STATUS/

Apologies,
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre