[Intel-gfx] [PATCH] drm/i915: PF CRC may not work on HSW

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

When using pipe A and transcoder EDP w/o panel fitter on
HSW, the PF CRC isn't available as the panel fitter is entirely
bypassed. Check for this and refuse to give out CRCs.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4242096..0535cbd 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2454,7 +2454,30 @@ 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 bool hsw_crc_source_pf_ok(struct drm_device *dev, enum pipe pipe)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
+	bool ok;
+
+	if (!IS_HASWELL(dev) || pipe != PIPE_A)
+		return true;
+
+	mutex_lock(&crtc->base.mutex);
+
+	/* pipe A -> no panel fitter -> transcoder EDP == no PF CRC */
+	ok = !crtc->active ||
+		crtc->config.cpu_transcoder != TRANSCODER_EDP ||
+		crtc->config.pch_pfit.enabled;
+
+	mutex_unlock(&crtc->base.mutex);
+
+	return ok;
+}
+
+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)
@@ -2468,6 +2491,8 @@ 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 (!hsw_crc_source_pf_ok(dev, pipe))
+			return -EINVAL;
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
 		break;
 	case INTEL_PIPE_CRC_SOURCE_NONE:
@@ -2504,7 +2529,7 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 	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;
-- 
1.8.3.2