drm/i915/dc3co: Avoid full modeset when EXITLINE needs to be changed

A recent change in BSpec allow us to change EXTLINE while transcoder
is enabled so this allow us to change it even when doing the first
fastset after taking over previous hardware state set by BIOS.
BIOS don't enable PSR, so if sink supports PSR it will be enabled on
the first fastset, so moving the EXTLINE compute and set to PSR flows
allow us to simplfy a bunch of code.

This will save a lot of time in all the IGT tests that uses CRC, as
when PSR2 is enabled CRCs are not generated, so we switch to PSR1, so
the previous code would compute dc3co_exitline=0 causing a full
modeset that would shutdown pipe, enable and train link.

v2: only programming EXTLINE when DC3CO is enabled

BSpec: 49196
Cc: Imre Deak <imre.deak@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200122182617.18597-2-jose.souza@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -3345,86 +3345,6 @@ static void intel_ddi_disable_fec_state(struct intel_encoder *encoder,
 	POSTING_READ(intel_dp->regs.dp_tp_ctl);
 }
 
-static void
-tgl_clear_psr2_transcoder_exitline(const struct intel_crtc_state *cstate)
-{
-	struct drm_i915_private *dev_priv = to_i915(cstate->uapi.crtc->dev);
-	u32 val;
-
-	if (!cstate->dc3co_exitline)
-		return;
-
-	val = I915_READ(EXITLINE(cstate->cpu_transcoder));
-	val &= ~(EXITLINE_MASK | EXITLINE_ENABLE);
-	I915_WRITE(EXITLINE(cstate->cpu_transcoder), val);
-}
-
-static void
-tgl_set_psr2_transcoder_exitline(const struct intel_crtc_state *cstate)
-{
-	u32 val, exit_scanlines;
-	struct drm_i915_private *dev_priv = to_i915(cstate->uapi.crtc->dev);
-
-	if (!cstate->dc3co_exitline)
-		return;
-
-	exit_scanlines = cstate->dc3co_exitline;
-	exit_scanlines <<= EXITLINE_SHIFT;
-	val = I915_READ(EXITLINE(cstate->cpu_transcoder));
-	val &= ~(EXITLINE_MASK | EXITLINE_ENABLE);
-	val |= exit_scanlines;
-	val |= EXITLINE_ENABLE;
-	I915_WRITE(EXITLINE(cstate->cpu_transcoder), val);
-}
-
-static void tgl_dc3co_exitline_compute_config(struct intel_encoder *encoder,
-					      struct intel_crtc_state *cstate)
-{
-	u32 exit_scanlines;
-	struct drm_i915_private *dev_priv = to_i915(cstate->uapi.crtc->dev);
-	u32 crtc_vdisplay = cstate->hw.adjusted_mode.crtc_vdisplay;
-
-	cstate->dc3co_exitline = 0;
-
-	if (!(dev_priv->csr.allowed_dc_mask & DC_STATE_EN_DC3CO))
-		return;
-
-	/* B.Specs:49196 DC3CO only works with pipeA and DDIA.*/
-	if (to_intel_crtc(cstate->uapi.crtc)->pipe != PIPE_A ||
-	    encoder->port != PORT_A)
-		return;
-
-	if (!cstate->has_psr2 || !cstate->hw.active)
-		return;
-
-	/*
-	 * DC3CO Exit time 200us B.Spec 49196
-	 * PSR2 transcoder Early Exit scanlines = ROUNDUP(200 / line time) + 1
-	 */
-	exit_scanlines =
-		intel_usecs_to_scanlines(&cstate->hw.adjusted_mode, 200) + 1;
-
-	if (WARN_ON(exit_scanlines > crtc_vdisplay))
-		return;
-
-	cstate->dc3co_exitline = crtc_vdisplay - exit_scanlines;
-	DRM_DEBUG_KMS("DC3CO exit scanlines %d\n", cstate->dc3co_exitline);
-}
-
-static void tgl_dc3co_exitline_get_config(struct intel_crtc_state *crtc_state)
-{
-	u32 val;
-	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
-
-	if (INTEL_GEN(dev_priv) < 12)
-		return;
-
-	val = I915_READ(EXITLINE(crtc_state->cpu_transcoder));
-
-	if (val & EXITLINE_ENABLE)
-		crtc_state->dc3co_exitline = val & EXITLINE_MASK;
-}
-
 static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
 				  const struct intel_crtc_state *crtc_state,
 				  const struct drm_connector_state *conn_state)
@@ -3437,7 +3357,6 @@ static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
 	int level = intel_ddi_dp_level(intel_dp);
 	enum transcoder transcoder = crtc_state->cpu_transcoder;
 
-	tgl_set_psr2_transcoder_exitline(crtc_state);
 	intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
 				 crtc_state->lane_count, is_mst);
 
@@ -3823,7 +3742,6 @@ static void intel_ddi_post_disable_dp(struct intel_encoder *encoder,
 						  dig_port->ddi_io_power_domain);
 
 	intel_ddi_clk_disable(encoder);
-	tgl_clear_psr2_transcoder_exitline(old_crtc_state);
 }
 
 static void intel_ddi_post_disable_hdmi(struct intel_encoder *encoder,
@@ -4407,9 +4325,6 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 		break;
 	}
 
-	if (encoder->type == INTEL_OUTPUT_EDP)
-		tgl_dc3co_exitline_get_config(pipe_config);
-
 	pipe_config->has_audio =
 		intel_ddi_is_audio_enabled(dev_priv, cpu_transcoder);
 
@@ -4491,7 +4406,6 @@ static int intel_ddi_compute_config(struct intel_encoder *encoder,
 		ret = intel_hdmi_compute_config(encoder, pipe_config, conn_state);
 	} else {
 		ret = intel_dp_compute_config(encoder, pipe_config, conn_state);
-		tgl_dc3co_exitline_compute_config(encoder, pipe_config);
 	}
 
 	if (ret)

drivers/gpu/drm/i915/display/intel_display.c

@@ -13579,7 +13579,6 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 
 	PIPE_CONF_CHECK_I(pixel_multiplier);
 	PIPE_CONF_CHECK_I(output_format);
-	PIPE_CONF_CHECK_I(dc3co_exitline);
 	PIPE_CONF_CHECK_BOOL(has_hdmi_sink);
 	if ((INTEL_GEN(dev_priv) < 8 && !IS_HASWELL(dev_priv)) ||
 	    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))

drivers/gpu/drm/i915/display/intel_psr.c

@@ -600,6 +600,36 @@ static void tgl_disallow_dc3co_on_psr2_exit(struct drm_i915_private *dev_priv)
 	tgl_psr2_disable_dc3co(dev_priv);
 }
 
+static void
+tgl_dc3co_exitline_compute_config(struct intel_dp *intel_dp,
+				  struct intel_crtc_state *crtc_state)
+{
+	const u32 crtc_vdisplay = crtc_state->uapi.adjusted_mode.crtc_vdisplay;
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+	u32 exit_scanlines;
+
+	if (!(dev_priv->csr.allowed_dc_mask & DC_STATE_EN_DC3CO))
+		return;
+
+	/* B.Specs:49196 DC3CO only works with pipeA and DDIA.*/
+	if (to_intel_crtc(crtc_state->uapi.crtc)->pipe != PIPE_A ||
+	    dig_port->base.port != PORT_A)
+		return;
+
+	/*
+	 * DC3CO Exit time 200us B.Spec 49196
+	 * PSR2 transcoder Early Exit scanlines = ROUNDUP(200 / line time) + 1
+	 */
+	exit_scanlines =
+		intel_usecs_to_scanlines(&crtc_state->uapi.adjusted_mode, 200) + 1;
+
+	if (WARN_ON(exit_scanlines > crtc_vdisplay))
+		return;
+
+	crtc_state->dc3co_exitline = crtc_vdisplay - exit_scanlines;
+}
+
 static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 				    struct intel_crtc_state *crtc_state)
 {
@@ -671,6 +701,7 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 		return false;
 	}
 
+	tgl_dc3co_exitline_compute_config(intel_dp, crtc_state);
 	return true;
 }
 
@@ -788,6 +819,20 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
 	I915_WRITE(EDP_PSR_DEBUG(dev_priv->psr.transcoder), mask);
 
 	psr_irq_control(dev_priv);
+
+	if (crtc_state->dc3co_exitline) {
+		u32 val;
+
+		/*
+		 * TODO: if future platforms supports DC3CO in more than one
+		 * transcoder, EXITLINE will need to be unset when disabling PSR
+		 */
+		val = I915_READ(EXITLINE(cpu_transcoder));
+		val &= ~EXITLINE_MASK;
+		val |= crtc_state->dc3co_exitline << EXITLINE_SHIFT;
+		val |= EXITLINE_ENABLE;
+		I915_WRITE(EXITLINE(cpu_transcoder), val);
+	}
 }
 
 static void intel_psr_enable_locked(struct drm_i915_private *dev_priv,