[Intel-gfx] [PATCH] drm/i915: Support pf CRC source on haswell transcoder edp

[Daniel Vetter]

The always-on power well pixel path on haswell is routed such that it
bypasses the panel fitter when we use is. Which means the pfit CRC
source won't work in that configuration.

Add a new disallow-bypass flags to the pfit pipe config state and set
it when we want to use the pf CRC. Results in a bit of flicker, but
should get the job done. We'll also undo do it afterwards to make sure
other tests arent' negatively affected.

Totally untested due to lack of hsw laptops around here.

v2: s/disallow_bypass/force_power_well_on/ to avoid a double negative
(Damien).

v3: force_thru because roadsigns.

References: https://bugs.freedesktop.org/show_bug.cgi?id=72864
Cc: Damien Lespiau <damien.lespiau at intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 58 +++++++++++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/intel_ddi.c    |  3 +-
 drivers/gpu/drm/i915/intel_drv.h    |  1 +
 3 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 195fe5bc0aac..105d4f5d792e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2829,7 +2829,54 @@ static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
 	return 0;
 }
 
-static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
+static void hsw_trans_edp_pipe_A_crc_wa(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc =
+		to_intel_crtc(dev_priv->pipe_to_crtc_mapping[PIPE_A]);
+
+	drm_modeset_lock_all(dev);
+	/*
+	 * If we use the eDP transcoder we need to make sure that we don't
+	 * bypass the pfit, since otherwise the pipe CRC source won't work. Only
+	 * relevant on hsw with pipe A when using the always-on power well
+	 * routing.
+	 */
+	if (crtc->config.cpu_transcoder == TRANSCODER_EDP &&
+	    !crtc->config.pch_pfit.enabled) {
+		crtc->config.pch_pfit.force_thru = true;
+
+		dev_priv->display.crtc_disable(&crtc->base);
+		dev_priv->display.crtc_enable(&crtc->base);
+	}
+	drm_modeset_unlock_all(dev);
+}
+
+static void hsw_undo_trans_edp_pipe_A_crc_wa(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc =
+		to_intel_crtc(dev_priv->pipe_to_crtc_mapping[PIPE_A]);
+
+	drm_modeset_lock_all(dev);
+	/*
+	 * If we use the eDP transcoder we need to make sure that we don't
+	 * bypass the pfit, since otherwise the pipe CRC source won't work. Only
+	 * relevant on hsw with pipe A when using the always-on power well
+	 * routing.
+	 */
+	if (crtc->config.pch_pfit.force_thru) {
+		crtc->config.pch_pfit.force_thru = false;
+
+		dev_priv->display.crtc_disable(&crtc->base);
+		dev_priv->display.crtc_enable(&crtc->base);
+	}
+	drm_modeset_unlock_all(dev);
+}
+
+static int ivb_pipe_crc_ctl_reg(struct drm_device *dev,
+				enum pipe pipe,
+				enum intel_pipe_crc_source *source,
 				uint32_t *val)
 {
 	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
@@ -2843,6 +2890,9 @@ static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
 		break;
 	case INTEL_PIPE_CRC_SOURCE_PF:
+		if (IS_HASWELL(dev) && pipe == PIPE_A)
+			hsw_trans_edp_pipe_A_crc_wa(dev);
+
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
 		break;
 	case INTEL_PIPE_CRC_SOURCE_NONE:
@@ -2875,11 +2925,11 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 	else if (INTEL_INFO(dev)->gen < 5)
 		ret = i9xx_pipe_crc_ctl_reg(dev, pipe, &source, &val);
 	else if (IS_VALLEYVIEW(dev))
-		ret = vlv_pipe_crc_ctl_reg(dev,pipe, &source, &val);
+		ret = vlv_pipe_crc_ctl_reg(dev, pipe, &source, &val);
 	else if (IS_GEN5(dev) || IS_GEN6(dev))
 		ret = ilk_pipe_crc_ctl_reg(&source, &val);
 	else
-		ret = ivb_pipe_crc_ctl_reg(&source, &val);
+		ret = ivb_pipe_crc_ctl_reg(dev, pipe, &source, &val);
 
 	if (ret != 0)
 		return ret;
@@ -2926,6 +2976,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 			g4x_undo_pipe_scramble_reset(dev, pipe);
 		else if (IS_VALLEYVIEW(dev))
 			vlv_undo_pipe_scramble_reset(dev, pipe);
+		else if (IS_HASWELL(dev) && pipe == PIPE_A)
+			hsw_undo_trans_edp_pipe_A_crc_wa(dev);
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 0ad4e9600063..52ec76ad1b21 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1044,7 +1044,8 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 			 * eDP when not using the panel fitter, and when not
 			 * using motion blur mitigation (which we don't
 			 * support). */
-			if (IS_HASWELL(dev) && intel_crtc->config.pch_pfit.enabled)
+			if (IS_HASWELL(dev) && intel_crtc->config.pch_pfit.enabled ||
+			    intel_crtc->config.pch_pfit.force_thru)
 				temp |= TRANS_DDI_EDP_INPUT_A_ONOFF;
 			else
 				temp |= TRANS_DDI_EDP_INPUT_A_ON;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0542de982260..dca16322558b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -327,6 +327,7 @@ struct intel_crtc_config {
 		u32 pos;
 		u32 size;
 		bool enabled;
+		bool force_thru;
 	} pch_pfit;
 
 	/* FDI configuration, only valid if has_pch_encoder is set. */
-- 
1.9.2