video: tegra: add cursor mode flipping

This change adds a flag to flip windows in cursor mode.  Cursor mode
will cause flips to be skipped over if there are newer flip requests
waiting in the workqueue.

Add CURSOR_MODE to caps bitfield.

bug 942762

Change-Id: Ib52a0a5565f961cdd9650e4204cd65b86f96fee1
Signed-off-by: Adam Cheney <acheney@nvidia.com>
Reviewed-on: http://git-master/r/90418
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Robert Morell <rmorell@nvidia.com>

2 files changed, 31 insertions, 8 deletions

diff --git a/drivers/video/tegra/dc/ext/dev.c b/drivers/video/tegra/dc/ext/dev.c
index 24e62ca15a72..04553e778390 100644
--- a/drivers/video/tegra/dc/ext/dev.c
+++ b/drivers/video/tegra/dc/ext/dev.c
@@ -243,7 +243,9 @@ static void tegra_dc_ext_flip_worker(struct work_struct *work)
 	struct tegra_dc_win *wins[DC_N_WINDOWS];
 	struct nvmap_handle_ref *unpin_handles[DC_N_WINDOWS *
 					       TEGRA_DC_NUM_PLANES];
+	struct nvmap_handle_ref *old_handle;
 	int i, nr_unpin = 0, nr_win = 0;
+	bool skip_flip = false;
 
 	for (i = 0; i < DC_N_WINDOWS; i++) {
 		struct tegra_dc_ext_flip_win *flip_win = &data->win[i];
@@ -257,25 +259,36 @@ static void tegra_dc_ext_flip_worker(struct work_struct *work)
 		win = tegra_dc_get_window(ext->dc, index);
 		ext_win = &ext->win[index];
 
+		if (!(atomic_dec_and_test(&ext_win->nr_pending_flips)) &&
+			(flip_win->attr.flags & TEGRA_DC_EXT_FLIP_FLAG_CURSOR))
+			skip_flip = true;
+
 		if (win->flags & TEGRA_WIN_FLAG_ENABLED) {
 			int j;
 			for (j = 0; j < TEGRA_DC_NUM_PLANES; j++) {
-				if (!ext_win->cur_handle[j])
+				if (skip_flip)
+					old_handle = flip_win->handle[j];
+				else
+					old_handle = ext_win->cur_handle[j];
+
+				if (!old_handle)
 					continue;
 
-				unpin_handles[nr_unpin++] =
-					ext_win->cur_handle[j];
+				unpin_handles[nr_unpin++] = old_handle;
 			}
 		}
 
-		tegra_dc_ext_set_windowattr(ext, win, &data->win[i]);
+		if (!skip_flip)
+			tegra_dc_ext_set_windowattr(ext, win, &data->win[i]);
 
 		wins[nr_win++] = win;
 	}
 
-	tegra_dc_update_windows(wins, nr_win);
-	/* TODO: implement swapinterval here */
-	tegra_dc_sync_windows(wins, nr_win);
+	if (!skip_flip) {
+		tegra_dc_update_windows(wins, nr_win);
+		/* TODO: implement swapinterval here */
+		tegra_dc_sync_windows(wins, nr_win);
+	}
 
 	for (i = 0; i < DC_N_WINDOWS; i++) {
 		struct tegra_dc_ext_flip_win *flip_win = &data->win[i];
@@ -484,10 +497,15 @@ static int tegra_dc_ext_flip(struct tegra_dc_ext_user *user,
 	for (i = 0; i < DC_N_WINDOWS; i++) {
 		u32 syncpt_max;
 		int index = args->win[i].index;
+		struct tegra_dc_win *win;
+		struct tegra_dc_ext_win *ext_win;
 
 		if (index < 0)
 			continue;
 
+		win = tegra_dc_get_window(ext->dc, index);
+		ext_win = &ext->win[index];
+
 		syncpt_max = tegra_dc_incr_syncpt_max(ext->dc, index);
 
 		data->win[i].syncpt_max = syncpt_max;
@@ -499,6 +517,8 @@ static int tegra_dc_ext_flip(struct tegra_dc_ext_user *user,
 		args->post_syncpt_val = syncpt_max;
 		args->post_syncpt_id = tegra_dc_get_syncpt_id(ext->dc, index);
 		work_index = index;
+
+		atomic_inc(&ext->win[work_index].nr_pending_flips);
 	}
 	queue_work(ext->win[work_index].flip_wq, &data->work);
 
diff --git a/drivers/video/tegra/dc/ext/tegra_dc_ext_priv.h b/drivers/video/tegra/dc/ext/tegra_dc_ext_priv.h
index abebd5970ecb..95a637d5a52a 100644
--- a/drivers/video/tegra/dc/ext/tegra_dc_ext_priv.h
+++ b/drivers/video/tegra/dc/ext/tegra_dc_ext_priv.h
@@ -56,6 +56,8 @@ struct tegra_dc_ext_win {
 	struct nvmap_handle_ref	*cur_handle[TEGRA_DC_NUM_PLANES];
 
 	struct workqueue_struct	*flip_wq;
+
+	atomic_t		nr_pending_flips;
 };
 
 struct tegra_dc_ext {
@@ -90,7 +92,8 @@ struct tegra_dc_ext_event_list {
 	struct list_head		list;
 };
 
-#define TEGRA_DC_EXT_CAPABILITIES	0
+#define TEGRA_DC_EXT_CAPABILITIES \
+	TEGRA_DC_EXT_CAPABILITIES_CURSOR_MODE
 
 struct tegra_dc_ext_control_user {
 	struct tegra_dc_ext_control	*control;