[Intel-gfx] [PATCH 2/6] drm/i915: Align vswing sequences with old ddi buffer registers.

[Rodrigo Vivi]

Vswing sequences on BXT and CNL are equivalent
to the ddi buffer registers setting on other platforms.

For some reason it got aligned with skl_ddi_set_iboost what
is semantically incorrect. This forced us to keep skipping
ddi buffer translation tables on the platforms that has
the vswing sequences.

Cc: Vandana Kannan <vandana.kannan at intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Ander Conselvan de Oliveira <conselvan2 at gmail.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index d7594bb16bfc..687b762d1b53 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -688,9 +688,6 @@ static void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder)
 	enum port port = intel_ddi_get_encoder_port(encoder);
 	const struct ddi_buf_trans *ddi_translations;
 
-	if (IS_GEN9_LP(dev_priv))
-		return;
-
 	switch (encoder->type) {
 	case INTEL_OUTPUT_EDP:
 		ddi_translations = intel_ddi_get_buf_trans_edp(dev_priv,
@@ -741,9 +738,6 @@ static void intel_prepare_hdmi_ddi_buffers(struct intel_encoder *encoder)
 	enum port port = intel_ddi_get_encoder_port(encoder);
 	const struct ddi_buf_trans *ddi_translations_hdmi;
 
-	if (IS_GEN9_LP(dev_priv))
-		return;
-
 	hdmi_level = intel_ddi_hdmi_level(dev_priv, port);
 
 	if (IS_GEN9_BC(dev_priv)) {
@@ -2068,18 +2062,11 @@ uint32_t ddi_signal_levels(struct intel_dp *intel_dp)
 	struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
 	struct drm_i915_private *dev_priv = to_i915(dport->base.base.dev);
 	struct intel_encoder *encoder = &dport->base;
-	enum port port = dport->port;
 	uint32_t level = intel_ddi_dp_level(intel_dp);
 
 	if (IS_GEN9_BC(dev_priv))
 		skl_ddi_set_iboost(encoder, level);
-	else if (IS_GEN9_LP(dev_priv))
-		bxt_ddi_vswing_sequence(dev_priv, level, port, encoder->type);
-	else if (IS_CANNONLAKE(dev_priv)) {
-		cnl_ddi_vswing_sequence(encoder, level);
-		/* DDI_BUF_CTL bits 27:24 are reserved on CNL */
-		return 0;
-	}
+
 	return DDI_BUF_TRANS_SELECT(level);
 }
 
@@ -2133,6 +2120,7 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	enum port port = intel_ddi_get_encoder_port(encoder);
 	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
+	uint32_t level = intel_ddi_dp_level(intel_dp);
 
 	WARN_ON(link_mst && (port == PORT_A || port == PORT_E));
 
@@ -2145,7 +2133,13 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 
 	intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain);
 
-	intel_prepare_dp_ddi_buffers(encoder);
+	if (IS_CANNONLAKE(dev_priv))
+		cnl_ddi_vswing_sequence(encoder, level);
+	else if (IS_GEN9_LP(dev_priv))
+		bxt_ddi_vswing_sequence(dev_priv, level, port, encoder->type);
+	else
+		intel_prepare_dp_ddi_buffers(encoder);
+
 	intel_ddi_init_dp_buf_reg(encoder);
 	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 	intel_dp_start_link_train(intel_dp);
@@ -2171,14 +2165,16 @@ static void intel_ddi_pre_enable_hdmi(struct intel_encoder *encoder,
 
 	intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain);
 
-	intel_prepare_hdmi_ddi_buffers(encoder);
-	if (IS_GEN9_BC(dev_priv))
-		skl_ddi_set_iboost(encoder, level);
+	if (IS_CANNONLAKE(dev_priv))
+		cnl_ddi_vswing_sequence(encoder, level);
 	else if (IS_GEN9_LP(dev_priv))
 		bxt_ddi_vswing_sequence(dev_priv, level, port,
 					INTEL_OUTPUT_HDMI);
-	else if (IS_CANNONLAKE(dev_priv))
-		cnl_ddi_vswing_sequence(encoder, level);
+	else
+		intel_prepare_hdmi_ddi_buffers(encoder);
+
+	if (IS_GEN9_BC(dev_priv))
+		skl_ddi_set_iboost(encoder, level);
 
 	intel_hdmi->set_infoframes(drm_encoder,
 				   has_hdmi_sink,
-- 
2.13.2