On Thu, Jan 6, 2011 at 18:49, Chris Wilson <chris at 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
