[F/OEM-5.6] [PATCH 1/3] drm/i915/dpcd_bl: Unbreak enable_dpcd_backlight modparam

[Kai-Heng Feng]

From: Lyude Paul <lyude at redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1898865

Looks like I accidentally made it so you couldn't force DPCD backlight
support on, whoops. Fix that.

Signed-off-by: Lyude Paul <lyude at redhat.com>
Fixes: 17f5d57915be ("drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel")
Cc: Adam Jackson <ajax at redhat.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: "Ville Syrjälä" <ville.syrjala at linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200413214407.1851002-1-lyude@redhat.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index af6ee93aaed4..50abd2afc133 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -339,6 +339,7 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 	 */
 	if (dev_priv->vbt.backlight.type !=
 	    INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
+	    i915_modparams.enable_dpcd_backlight != 1 &&
 	    !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks,
 			      DP_QUIRK_FORCE_DPCD_BACKLIGHT)) {
 		DRM_DEV_INFO(dev->dev,
-- 
2.17.1