drm/i915: push DDI CRT underrun reporting on disable to encoder

CRT being the only PCH encoder, we can simplify the crtc disable by
pushing the PCH encoder specific parts to CRT encoder.

v2: add hsw_disable_crt (Daniel), rebase

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1ecbbb946f7b3782ee3d97f0ec2fe4758c349311.1507200657.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_crt.c

@@ -213,6 +213,19 @@ static void pch_post_disable_crt(struct intel_encoder *encoder,
 	intel_disable_crt(encoder, old_crtc_state, old_conn_state);
 }
 
+static void hsw_disable_crt(struct intel_encoder *encoder,
+			    const struct intel_crtc_state *old_crtc_state,
+			    const struct drm_connector_state *old_conn_state)
+{
+	struct drm_crtc *crtc = old_crtc_state->base.crtc;
+	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	WARN_ON(!intel_crtc->config->has_pch_encoder);
+
+	intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, false);
+}
+
 static void hsw_post_disable_crt(struct intel_encoder *encoder,
 				 const struct intel_crtc_state *old_crtc_state,
 				 const struct drm_connector_state *old_conn_state)
@@ -225,6 +238,10 @@ static void hsw_post_disable_crt(struct intel_encoder *encoder,
 	lpt_disable_iclkip(dev_priv);
 
 	intel_ddi_fdi_post_disable(encoder, old_crtc_state, old_conn_state);
+
+	WARN_ON(!old_crtc_state->has_pch_encoder);
+
+	intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, true);
 }
 
 static void hsw_pre_pll_enable_crt(struct intel_encoder *encoder,
@@ -953,6 +970,7 @@ void intel_crt_init(struct drm_i915_private *dev_priv)
 		crt->base.pre_pll_enable = hsw_pre_pll_enable_crt;
 		crt->base.pre_enable = hsw_pre_enable_crt;
 		crt->base.enable = hsw_enable_crt;
+		crt->base.disable = hsw_disable_crt;
 		crt->base.post_disable = hsw_post_disable_crt;
 	} else {
 		crt->base.port = PORT_NONE;

drivers/gpu/drm/i915/intel_display.c

@@ -5669,9 +5669,6 @@ static void haswell_crtc_disable(struct intel_crtc_state *old_crtc_state,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
 
-	if (intel_crtc->config->has_pch_encoder)
-		intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, false);
-
 	intel_encoders_disable(crtc, old_crtc_state, old_state);
 
 	drm_crtc_vblank_off(crtc);
@@ -5696,9 +5693,6 @@ static void haswell_crtc_disable(struct intel_crtc_state *old_crtc_state,
 		intel_ddi_disable_pipe_clock(intel_crtc->config);
 
 	intel_encoders_post_disable(crtc, old_crtc_state, old_state);
-
-	if (old_crtc_state->has_pch_encoder)
-		intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, true);
 }
 
 static void i9xx_pfit_enable(struct intel_crtc *crtc)