[Intel-gfx] [PATCH v2 14/14] drm/i915/fbc: Reallocate cfb if we need more of it

[Ville Syrjala]

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

The code assumes we can omit the cfb allocation once fbc
has been enabled once. That's nonsense. Let's try to
reallocate it if we need to.

The code is still a mess, but maybe this is enough to get
fbc going in some cases where it initially underallocates
the cfb and there's no full modeset to fix it up.

Cc: Daniel Drake <drake at endlessm.com>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Jian-Hong Pan <jian-hong at endlessm.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_fbc.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index c976698b0729..928059a5da80 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -672,6 +672,14 @@ static void intel_fbc_update_state_cache(struct intel_crtc *crtc,
 		cache->fence_id = -1;
 }
 
+static bool intel_fbc_cfb_size_changed(struct drm_i915_private *dev_priv)
+{
+	struct intel_fbc *fbc = &dev_priv->fbc;
+
+	return intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache) >
+		fbc->compressed_fb.size * fbc->threshold;
+}
+
 static bool intel_fbc_can_activate(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
@@ -757,8 +765,7 @@ static bool intel_fbc_can_activate(struct intel_crtc *crtc)
 	 * we didn't get any invalidate/deactivate calls, but this would require
 	 * a lot of tracking just for a specific case. If we conclude it's an
 	 * important case, we can implement it later. */
-	if (intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache) >
-	    fbc->compressed_fb.size * fbc->threshold) {
+	if (intel_fbc_cfb_size_changed(dev_priv)) {
 		fbc->no_fbc_reason = "CFB requirements changed";
 		return false;
 	}
@@ -1112,12 +1119,12 @@ void intel_fbc_enable(struct intel_crtc *crtc,
 	mutex_lock(&fbc->lock);
 
 	if (fbc->crtc) {
-		WARN_ON(fbc->crtc == crtc && !crtc_state->enable_fbc);
-		goto out;
-	}
+		if (fbc->crtc != crtc ||
+		    !intel_fbc_cfb_size_changed(dev_priv))
+			goto out;
 
-	if (!crtc_state->enable_fbc)
-		goto out;
+		__intel_fbc_disable(dev_priv);
+	}
 
 	WARN_ON(fbc->active);
 
@@ -1130,6 +1137,7 @@ void intel_fbc_enable(struct intel_crtc *crtc,
 	if (intel_fbc_alloc_cfb(dev_priv,
 				intel_fbc_calculate_cfb_size(dev_priv, cache),
 				fb->format->cpp[0])) {
+		cache->plane.visible = false;
 		fbc->no_fbc_reason = "not enough stolen memory";
 		goto out;
 	}
-- 
2.23.0