drm: Reorganize drm_pending_event to support future event types [v2]

PD#SWPL-4863

Place drm_event_vblank in a new union that includes that and a bare
drm_event structure. This will allow new members of that union to be
added in the future without changing code related to the existing vbl
event type.

Assignments to the crtc_id field are now done when the event is
allocated, rather than when delievered. This way, delivery doesn't
need to have the crtc ID available.

v2:
 * Remove 'dev' argument from create_vblank_event

	It wasn't being used anyways, and if we need it in the future,
	we can always get it from crtc->dev.

 * Check for MODESETTING before looking for crtc in queue_vblank_event

	UMS drivers will oops if we try to get a crtc, so make sure
	we're modesetting before we try to find a crtc_id to fill into
	the event.

(cherry picked from commit dc695b85fde88eca3ef3b03fcd82f15b6bc6e462)

Change-Id: I6f0feabcba9373fcc434b148752d9cd28bea67e6
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Ao Xu <ao.xu@amlogic.com>

4 files changed, 32 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index b3f8543..8669712 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1654,7 +1654,7 @@ EXPORT_SYMBOL(drm_atomic_nonblocking_commit);
  */
 
 static struct drm_pending_vblank_event *create_vblank_event(
-		struct drm_device *dev, uint64_t user_data)
+		struct drm_crtc *crtc, uint64_t user_data)
 {
 	struct drm_pending_vblank_event *e = NULL;
 
@@ -1665,6 +1665,7 @@ static struct drm_pending_vblank_event *create_vblank_event(
 	e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
 	e->event.base.length = sizeof(e->event);
 	e->event.user_data = user_data;
+	e->event.crtc_id = crtc->base.id;
 
 	return e;
 }
@@ -1867,7 +1868,7 @@ static int prepare_crtc_signaling(struct drm_device *dev,
 		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
 			struct drm_pending_vblank_event *e;
 
-			e = create_vblank_event(dev, arg->user_data);
+			e = create_vblank_event(crtc, arg->user_data);
 			if (!e)
 				return -ENOMEM;
 
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index ebdef0c..de4fd23 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -47,6 +47,29 @@
 #include "drm_internal.h"
 
 /**
+ * drm_crtc_from_index - find the registered CRTC at an index
+ * @dev: DRM device
+ * @idx: index of registered CRTC to find for
+ *
+ * Given a CRTC index, return the registered CRTC from DRM device's
+ * list of CRTCs with matching index. This is the inverse of drm_crtc_index().
+ * It's useful in the vblank callbacks (like &drm_driver.enable_vblank or
+ * &drm_driver.disable_vblank), since that still deals with indices instead
+ * of pointers to &struct drm_crtc."
+ */
+struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx)
+{
+        struct drm_crtc *crtc;
+
+        drm_for_each_crtc(crtc, dev)
+                if (idx == crtc->index)
+                        return crtc;
+
+        return NULL;
+}
+EXPORT_SYMBOL(drm_crtc_from_index);
+
+/**
  * drm_crtc_force_disable - Forcibly turn off a CRTC
  * @crtc: CRTC to turn off
  *
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 28536aa..9a87bbe 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1578,6 +1578,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
 {
 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 	struct drm_pending_vblank_event *e;
+	struct drm_crtc *crtc;
 	struct timeval now;
 	unsigned long flags;
 	unsigned int seq;
@@ -1594,6 +1595,10 @@ static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
 	e->event.base.type = DRM_EVENT_VBLANK;
 	e->event.base.length = sizeof(e->event);
 	e->event.user_data = vblwait->request.signal;
+	e->event.crtc_id = 0;
+	crtc = drm_crtc_from_index(dev, pipe);
+	if (crtc)
+		e->event.crtc_id = crtc->base.id;
 
 	spin_lock_irqsave(&dev->event_lock, flags);
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index be7a15d..e2aa770 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -786,6 +786,7 @@ extern struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
 					       char topology[8]);
 extern void drm_mode_put_tile_group(struct drm_device *dev,
 				   struct drm_tile_group *tg);
+struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx);
 
 /* Helpers */
 static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev,