1 files changed, 8 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2bdfe4b2d6dc..16faea30114a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2790,16 +2790,6 @@ static void g4x_disable_dp(struct intel_encoder *encoder,
 			   const struct drm_connector_state *old_conn_state)
 {
 	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
-
-	/* disable the port before the pipe on g4x */
-	intel_dp_link_down(encoder, old_crtc_state);
-}
-
-static void ilk_disable_dp(struct intel_encoder *encoder,
-			   const struct intel_crtc_state *old_crtc_state,
-			   const struct drm_connector_state *old_conn_state)
-{
-	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
 }
 
 static void vlv_disable_dp(struct intel_encoder *encoder,
@@ -2813,13 +2803,19 @@ static void vlv_disable_dp(struct intel_encoder *encoder,
 	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
 }
 
-static void ilk_post_disable_dp(struct intel_encoder *encoder,
+static void g4x_post_disable_dp(struct intel_encoder *encoder,
 				const struct intel_crtc_state *old_crtc_state,
 				const struct drm_connector_state *old_conn_state)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
 	enum port port = encoder->port;
 
+	/*
+	 * Bspec does not list a specific disable sequence for g4x DP.
+	 * Follow the ilk+ sequence (disable pipe before the port) for
+	 * g4x DP as it does not suffer from underruns like the normal
+	 * g4x modeset sequence (disable pipe after the port).
+	 */
 	intel_dp_link_down(encoder, old_crtc_state);
 
 	/* Only ilk+ has port A */
@@ -6442,15 +6438,11 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
 		intel_encoder->enable = vlv_enable_dp;
 		intel_encoder->disable = vlv_disable_dp;
 		intel_encoder->post_disable = vlv_post_disable_dp;
-	} else if (INTEL_GEN(dev_priv) >= 5) {
-		intel_encoder->pre_enable = g4x_pre_enable_dp;
-		intel_encoder->enable = g4x_enable_dp;
-		intel_encoder->disable = ilk_disable_dp;
-		intel_encoder->post_disable = ilk_post_disable_dp;
 	} else {
 		intel_encoder->pre_enable = g4x_pre_enable_dp;
 		intel_encoder->enable = g4x_enable_dp;
 		intel_encoder->disable = g4x_disable_dp;
+		intel_encoder->post_disable = g4x_post_disable_dp;
 	}
 
 	intel_dig_port->dp.output_reg = output_reg;