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

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

v2: add separate hsw_enable_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/b117fb524fc571837c83292194fc2ad35e588ec9.1507200657.git.jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 9540702..6d57c92 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -227,6 +227,52 @@ static void hsw_post_disable_crt(struct intel_encoder *encoder,
 	intel_ddi_fdi_post_disable(encoder, old_crtc_state, old_conn_state);
 }
 
+static void hsw_pre_pll_enable_crt(struct intel_encoder *encoder,
+				   const struct intel_crtc_state *pipe_config,
+				   const struct drm_connector_state *conn_state)
+{
+	struct drm_crtc *crtc = pipe_config->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_pre_enable_crt(struct intel_encoder *encoder,
+			       const struct intel_crtc_state *pipe_config,
+			       const struct drm_connector_state *conn_state)
+{
+	struct drm_crtc *crtc = pipe_config->base.crtc;
+	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+
+	WARN_ON(!intel_crtc->config->has_pch_encoder);
+
+	intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false);
+}
+
+static void hsw_enable_crt(struct intel_encoder *encoder,
+			   const struct intel_crtc_state *pipe_config,
+			   const struct drm_connector_state *conn_state)
+{
+	struct drm_crtc *crtc = pipe_config->base.crtc;
+	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+
+	WARN_ON(!intel_crtc->config->has_pch_encoder);
+
+	intel_crt_set_dpms(encoder, pipe_config, DRM_MODE_DPMS_ON);
+
+	intel_wait_for_vblank(dev_priv, pipe);
+	intel_wait_for_vblank(dev_priv, pipe);
+	intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true);
+	intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, true);
+}
+
 static void intel_enable_crt(struct intel_encoder *encoder,
 			     const struct intel_crtc_state *pipe_config,
 			     const struct drm_connector_state *conn_state)
@@ -897,7 +943,6 @@ void intel_crt_init(struct drm_i915_private *dev_priv)
 	} else {
 		crt->base.disable = intel_disable_crt;
 	}
-	crt->base.enable = intel_enable_crt;
 	if (I915_HAS_HOTPLUG(dev_priv) &&
 	    !dmi_check_system(intel_spurious_crt_detect))
 		crt->base.hpd_pin = HPD_CRT;
@@ -905,11 +950,15 @@ void intel_crt_init(struct drm_i915_private *dev_priv)
 		crt->base.port = PORT_E;
 		crt->base.get_config = hsw_crt_get_config;
 		crt->base.get_hw_state = intel_ddi_get_hw_state;
+		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.post_disable = hsw_post_disable_crt;
 	} else {
 		crt->base.port = PORT_NONE;
 		crt->base.get_config = intel_crt_get_config;
 		crt->base.get_hw_state = intel_crt_get_hw_state;
+		crt->base.enable = intel_enable_crt;
 	}
 	intel_connector->get_hw_state = intel_connector_get_hw_state;