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;