[PATCH 1/1] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc clock.

[Mitul Golani]

The dispcnlunit1_cp_xosc_clk should be de-asserted in display off
and only asserted in display on. But during observation it found
clk remains active in display OFF. As workaround, Display driver
shall execute set-reset sequence at the end of the Initialize
Sequence.

Wa_15013987218
---
 drivers/gpu/drm/i915/display/intel_display_power.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 03dc7edcc443..390750e14d4f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -1700,6 +1700,12 @@ static void icl_display_core_init(struct drm_i915_private *dev_priv,
 	/* Wa_14011503030:xelpd */
 	if (DISPLAY_VER(dev_priv) == 13)
 		intel_de_write(dev_priv, XELPD_DISPLAY_ERR_FATAL_MASK, ~0);
+	
+	/* Wa_14020225554 */
+	if (DISPLAY_VER(dev_priv) == 20) {
+		pch_gmbus_clock_gating(i915, false);
+		pch_gmbus_clock_gating(i915, true);
+	}
 }
 
 static void icl_display_core_uninit(struct drm_i915_private *dev_priv)
-- 
2.25.1