[Intel-gfx] [PATCH 1/7] drm/i915: fix CFB size calculation

[Paulo Zanoni]

We were considering the whole framebuffer height, but the spec clearly
says that we should only consider the active display height size.

On my current testing machine, this moves us from 124 successes and
502 skips to 209 successes and 417 skips on "kms_frontbuffer_tracking
--fbc-only". The high amount of skips is due to the --fbc-only
argument. We had those skips due to not enough stolen memory for the
tests. We're now passing the maximum possible amount: 209.

Note: when this patch was written, the amount of tests we had for FBC
was different than what we have now.

v2: Use the clipped src size instead of pipe_src_h (Ville).

Testcase: igt/kms_frontbuffer_tracking/fbc-*
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_fbc.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index d38f464..0a6b454 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -693,9 +693,15 @@ void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
 	mutex_unlock(&dev_priv->fbc.lock);
 }
 
-static int intel_fbc_setup_cfb(struct drm_i915_private *dev_priv, int size,
-			       int fb_cpp)
+static int intel_fbc_setup_cfb(struct intel_crtc *crtc)
 {
+	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+	struct drm_framebuffer *fb = crtc->base.primary->fb;
+	int size, fb_cpp;
+
+	size = (crtc->base.primary->state->src_h >> 16) * fb->pitches[0];
+	fb_cpp = drm_format_plane_cpp(fb->pixel_format, 0);
+
 	if (size <= dev_priv->fbc.uncompressed_size)
 		return 0;
 
@@ -883,8 +889,7 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 		goto out_disable;
 	}
 
-	if (intel_fbc_setup_cfb(dev_priv, obj->base.size,
-				drm_format_plane_cpp(fb->pixel_format, 0))) {
+	if (intel_fbc_setup_cfb(intel_crtc)) {
 		set_no_fbc_reason(dev_priv, FBC_STOLEN_TOO_SMALL);
 		goto out_disable;
 	}
-- 
2.5.1