[PATCH] drm/i915/display: Add WA_14018221282

[Nemesa Garg <nemesa.garg@intel.com>]

It was observed that the first write to DKL DP Mode register
was not taking effect, hence rewrite this register.

Signed-off-by: Nemesa Garg <nemesa.garg@intel.com>
Signed-off-by: Kulkarni, Vandita <vandita.kulkarni@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 769bd1f26db2..16a1d18f3aa1 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2104,6 +2104,16 @@ void intel_ddi_sanitize_encoder_pll_mapping(struct intel_encoder *encoder)
 	encoder->disable_clock(encoder);
 }
 
+static void
+tgl_wa_14018221282(struct drm_i915_private *dev_priv, enum tc_port tc_port,
+		   u32 ln0, u32 ln1)
+{
+	if (ln0 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 0)))
+		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
+	if (ln1 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 1)))
+		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1);
+}
+
 static void
 icl_program_mg_dp_mode(struct intel_digital_port *dig_port,
 		       const struct intel_crtc_state *crtc_state)
@@ -2185,6 +2195,10 @@ icl_program_mg_dp_mode(struct intel_digital_port *dig_port,
 	if (DISPLAY_VER(dev_priv) >= 12) {
 		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
 		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1);
+		 /* WA_14018221282 */
+		if (DISPLAY_VER(dev_priv) == 12)
+			tgl_wa_14018221282(dev_priv, tc_port, ln0, ln1);
+
 	} else {
 		intel_de_write(dev_priv, MG_DP_MODE(0, tc_port), ln0);
 		intel_de_write(dev_priv, MG_DP_MODE(1, tc_port), ln1);
-- 
2.25.1