drm/i915/fbc: fix the FBC state checking code

We'll now call intel_fbc_pre_update instead of intel_fbc_deactivate
during atomic commits. This will continue to guarantee that we
deactivate FBC and it will also update the state checking structures
at the correct time. Then, later, at the point where we were calling
intel_fbc_update, we'll only need to call intel_fbc_post_update.

Also add the proper warnings in case we don't have the appropriate
locks. Daniel mentioned the warnings will have to be removed for async
commits, but let's keep them here while we can.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453210558-7875-12-git-send-email-paulo.r.zanoni@intel.com

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 61523cd95ac1..1c26d65cdd33 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -510,6 +510,7 @@ static bool multiple_pipes_ok(struct drm_i915_private *dev_priv)
 	if (INTEL_INFO(dev_priv)->gen > 4)
 		return true;
 
+	/* FIXME: we don't have the appropriate state locks to do this here. */
 	for_each_pipe(dev_priv, pipe) {
 		crtc = dev_priv->pipe_to_crtc_mapping[pipe];
 
@@ -732,12 +733,16 @@ static void intel_fbc_update_state_cache(struct intel_crtc *crtc)
 	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
 	struct intel_fbc *fbc = &dev_priv->fbc;
 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
-	struct intel_crtc_state *crtc_state = crtc->config;
+	struct intel_crtc_state *crtc_state =
+		to_intel_crtc_state(crtc->base.state);
 	struct intel_plane_state *plane_state =
 		to_intel_plane_state(crtc->base.primary->state);
 	struct drm_framebuffer *fb = plane_state->base.fb;
 	struct drm_i915_gem_object *obj;
 
+	WARN_ON(!drm_modeset_is_locked(&crtc->base.mutex));
+	WARN_ON(!drm_modeset_is_locked(&crtc->base.primary->mutex));
+
 	cache->crtc.mode_flags = crtc_state->base.adjusted_mode.flags;
 	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
 		cache->crtc.hsw_bdw_pixel_rate =
@@ -896,12 +901,15 @@ static bool intel_fbc_reg_params_equal(struct intel_fbc_reg_params *params1,
 	return memcmp(params1, params2, sizeof(*params1)) == 0;
 }
 
-static void intel_fbc_pre_update(struct intel_crtc *crtc)
+void intel_fbc_pre_update(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
 	struct intel_fbc *fbc = &dev_priv->fbc;
 
-	WARN_ON(!mutex_is_locked(&fbc->lock));
+	if (!fbc_supported(dev_priv))
+		return;
+
+	mutex_lock(&fbc->lock);
 
 	if (!multiple_pipes_ok(dev_priv)) {
 		set_no_fbc_reason(dev_priv, "more than one pipe active");
@@ -909,15 +917,17 @@ static void intel_fbc_pre_update(struct intel_crtc *crtc)
 	}
 
 	if (!fbc->enabled || fbc->crtc != crtc)
-		return;
+		goto unlock;
 
 	intel_fbc_update_state_cache(crtc);
 
 deactivate:
 	__intel_fbc_deactivate(dev_priv);
+unlock:
+	mutex_unlock(&fbc->lock);
 }
 
-static void intel_fbc_post_update(struct intel_crtc *crtc)
+static void __intel_fbc_post_update(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
 	struct intel_fbc *fbc = &dev_priv->fbc;
@@ -950,13 +960,7 @@ static void intel_fbc_post_update(struct intel_crtc *crtc)
 	fbc->no_fbc_reason = "FBC enabled (active or scheduled)";
 }
 
-/*
- * intel_fbc_update - activate/deactivate FBC as needed
- * @crtc: the CRTC that triggered the update
- *
- * This function reevaluates the overall state and activates or deactivates FBC.
- */
-void intel_fbc_update(struct intel_crtc *crtc)
+void intel_fbc_post_update(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
 	struct intel_fbc *fbc = &dev_priv->fbc;
@@ -965,8 +969,7 @@ void intel_fbc_update(struct intel_crtc *crtc)
 		return;
 
 	mutex_lock(&fbc->lock);
-	intel_fbc_pre_update(crtc);
-	intel_fbc_post_update(crtc);
+	__intel_fbc_post_update(crtc);
 	mutex_unlock(&fbc->lock);
 }
 
@@ -1020,7 +1023,7 @@ void intel_fbc_flush(struct drm_i915_private *dev_priv,
 		if (fbc->active)
 			intel_fbc_recompress(dev_priv);
 		else
-			intel_fbc_post_update(fbc->crtc);
+			__intel_fbc_post_update(fbc->crtc);
 	}
 
 	mutex_unlock(&fbc->lock);