[PATCH 2/5][SRU][F] Revert "UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel"

[AceLan Kao]

BugLink: https://bugs.launchpad.net/bugs/1861521

This reverts commit 163215682f9be577adefacdc97ed3cd45af849e2.

Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
---
 drivers/gpu/drm/drm_dp_helper.c                       |  4 ----
 drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 10 ++--------
 include/drm/drm_dp_helper.h                           |  8 --------
 3 files changed, 2 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f1f14f4144e3..ffc68d305afe 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1260,10 +1260,6 @@ static const struct dpcd_quirk dpcd_quirk_list[] = {
 	{ OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) },
 	/* CH7511 seems to leave SINK_COUNT zeroed */
 	{ OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) },
-	/* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation
-	 * only supports DPCD backlight controls, despite advertising otherwise
-	 */
-	{ OUI(0xba, 0x41, 0x59), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT) },
 };
 
 #undef OUI
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 3d61260b08ad..87b59db9ffe3 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -325,17 +325,11 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
 int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 {
 	struct intel_panel *panel = &intel_connector->panel;
-	struct intel_dp *intel_dp =
-		enc_to_intel_dp(&intel_connector->encoder->base);
-	struct drm_i915_private *dev_priv =
-		to_i915(intel_connector->base.dev);
+	struct drm_i915_private *dev_priv = to_i915(intel_connector->base.dev);
 
 	if (i915_modparams.enable_dpcd_backlight == 0 ||
 	    (i915_modparams.enable_dpcd_backlight == -1 &&
-	     dev_priv->vbt.backlight.type !=
-		     INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
-	     !drm_dp_has_quirk(&intel_dp->desc,
-			       DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT)))
+	    dev_priv->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE))
 		return -ENODEV;
 
 	if (!intel_dp_aux_display_control_capable(intel_connector))
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index cd22d632fd74..8364502f92cf 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1434,14 +1434,6 @@ enum drm_dp_quirk {
 	 * The driver should ignore SINK_COUNT during detection.
 	 */
 	DP_DPCD_QUIRK_NO_SINK_COUNT,
-	/**
-	 * @DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT:
-	 *
-	 * The device is telling the truth when it says that it uses DPCD
-	 * backlight controls, even if the system's firmware disagrees.
-	 * The driver should honor the DPCD backlight capabilities advertised.
-	 */
-	DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT,
 };
 
 /**
-- 
2.17.1