drm/atomic: Add struct drm_crtc_commit to track async updates

Split out from my big nonblocking atomic commit helper code as prep
work. While add it, also add some neat asciiart to document how it's
supposed to be used.

v2: Resurrect misplaced hunk in the kerneldoc.

v3: Wording improvements from Liviu.

Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com>
Cc: Daniel Stone <daniels@collabora.com>
Tested-by: Liviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-8-git-send-email-daniel.vetter@ffwll.ch

3 files changed, 31 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 5e4b820a977c..d99ab2f6663f 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -33,6 +33,20 @@
 
 #include "drm_crtc_internal.h"
 
+static void crtc_commit_free(struct kref *kref)
+{
+	struct drm_crtc_commit *commit =
+		container_of(kref, struct drm_crtc_commit, ref);
+
+	kfree(commit);
+}
+
+void drm_crtc_commit_put(struct drm_crtc_commit *commit)
+{
+	kref_put(&commit->ref, crtc_commit_free);
+}
+EXPORT_SYMBOL(drm_crtc_commit_put);
+
 /**
  * drm_atomic_state_default_release -
  * release memory initialized by drm_atomic_state_init
@@ -148,6 +162,14 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
 
 		crtc->funcs->atomic_destroy_state(crtc,
 						  state->crtcs[i].state);
+
+		if (state->crtcs[i].commit) {
+			kfree(state->crtcs[i].commit->event);
+			state->crtcs[i].commit->event = NULL;
+			drm_crtc_commit_put(state->crtcs[i].commit);
+		}
+
+		state->crtcs[i].commit = NULL;
 		state->crtcs[i].ptr = NULL;
 		state->crtcs[i].state = NULL;
 	}
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index aeb5d9e087fc..4ec35f9e6de5 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -638,6 +638,9 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
 	crtc->dev = dev;
 	crtc->funcs = funcs;
 
+	INIT_LIST_HEAD(&crtc->commit_list);
+	spin_lock_init(&crtc->commit_lock);
+
 	drm_modeset_lock_init(&crtc->mutex);
 	ret = drm_mode_object_get(dev, &crtc->base, DRM_MODE_OBJECT_CRTC);
 	if (ret)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 64121f567234..a27bc7cda975 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -797,6 +797,12 @@ void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
 {
 	assert_spin_locked(&dev->event_lock);
 
+	if (e->completion) {
+		/* ->completion might disappear as soon as it signalled. */
+		complete_all(e->completion);
+		e->completion = NULL;
+	}
+
 	if (e->fence) {
 		fence_signal(e->fence);
 		fence_put(e->fence);