Re: [v2,2/3] drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel

On Tue, 2020-02-11 at 13:33 -0500, Lyude Paul wrote:

• if (!intel_dp_aux_display_control_capable(intel_connector))

• /*

• * There are a lot of machines that don't advertise the backlight
  

• * control interface to use properly in their VBIOS, :\
  

• */
  

• if (dev_priv->vbt.backlight.type !=

•    INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
  

•    !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks,
  

• 	      DP_QUIRK_FORCE_DPCD_BACKLIGHT)) {
  

• DRM_DEV_INFO(dev->dev,
  

• 	     "Panel advertises DPCD backlight support, but "
  

• 	     "VBT disagrees. If your backlight controls "
  

• 	     "don't work try booting with "
  

• 	     "i915.enable_dpcd_backlight=1. If your machine "
  

• 	     "needs this, please file a _new_ bug report on "
  

• 	     "bugs.freedesktop.org against DRI -> "
  

• 	     "DRM/Intel\n");
  

Bugzilla's been put out of our misery, probably this should point to gitlab instead.

- ajax