video: tegra: dc: disuse notifier

Due to issues with rcu notifiers on secureos, modifying dc flip
notifications to use a simple callback instead.

Bug 1028850

Change-Id: Iebf2a6d64d7316e3df2b88444201f9f9a29698c5
Signed-off-by: Ilan Aelion <iaelion@nvidia.com>
Reviewed-on: http://git-master/r/123103
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Nitin Kumbhar <nkumbhar@nvidia.com>

1 files changed, 10 insertions, 26 deletions

diff --git a/drivers/misc/tegra-throughput.c b/drivers/misc/tegra-throughput.c
index 26573d8afc1a..366b0ecc10e6 100644
--- a/drivers/misc/tegra-throughput.c
+++ b/drivers/misc/tegra-throughput.c
@@ -19,7 +19,6 @@
 
 #include <linux/kthread.h>
 #include <linux/ktime.h>
-#include <linux/notifier.h>
 #include <linux/miscdevice.h>
 #include <linux/fs.h>
 #include <linux/init.h>
@@ -45,12 +44,10 @@ static void set_throughput_hint(struct work_struct *work)
 	nvhost_scale3d_set_throughput_hint(throughput_hint);
 }
 
-static int throughput_flip_notifier(struct notifier_block *nb,
-					     unsigned long val,
-					     void *data)
+static int throughput_flip_callback(void)
 {
-	/* only register flips when a single display is active */
-	if (val != 1 || multiple_app_disable)
+	/* only register flips when a single app is active */
+	if (multiple_app_disable)
 		return NOTIFY_DONE;
 	else {
 		long timediff;
@@ -65,7 +62,7 @@ static int throughput_flip_notifier(struct notifier_block *nb,
 				last_frame_time = (unsigned short) timediff;
 
 			if (last_frame_time == 0) {
-				pr_warn("%s: notifications %lld nsec apart\n",
+				pr_warn("%s: flips %lld nsec apart\n",
 					__func__, now.tv64 - last_flip.tv64);
 				return NOTIFY_DONE;
 			}
@@ -82,10 +79,6 @@ static int throughput_flip_notifier(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block throughput_flip_nb = {
-	.notifier_call = throughput_flip_notifier,
-};
-
 static int sync_rate;
 static int throughput_active_app_count;
 
@@ -104,17 +97,15 @@ static void reset_target_frame_time(void)
 		__func__, sync_rate, target_frame_time);
 }
 
-static int notifier_initialized;
+static int callback_initialized;
 
 static int throughput_open(struct inode *inode, struct file *file)
 {
-	int need_init = 0;
-
 	spin_lock(&lock);
 
-	if (!notifier_initialized) {
-		notifier_initialized = 1;
-		need_init = 1;
+	if (!callback_initialized) {
+		callback_initialized = 1;
+		tegra_dc_set_flip_callback(throughput_flip_callback);
 	}
 
 	throughput_active_app_count++;
@@ -123,8 +114,6 @@ static int throughput_open(struct inode *inode, struct file *file)
 
 	spin_unlock(&lock);
 
-	if (need_init)
-		tegra_dc_register_flip_notifier(&throughput_flip_nb);
 
 	pr_debug("throughput_open node %p file %p\n", inode, file);
 
@@ -133,23 +122,18 @@ static int throughput_open(struct inode *inode, struct file *file)
 
 static int throughput_release(struct inode *inode, struct file *file)
 {
-	int need_deinit = 0;
-
 	spin_lock(&lock);
 
 	throughput_active_app_count--;
 	if (throughput_active_app_count == 0) {
 		reset_target_frame_time();
 		multiple_app_disable = 0;
-		notifier_initialized = 0;
-		need_deinit = 1;
+		callback_initialized = 0;
+		tegra_dc_unset_flip_callback();
 	}
 
 	spin_unlock(&lock);
 
-	if (need_deinit)
-		tegra_dc_unregister_flip_notifier(&throughput_flip_nb);
-
 	pr_debug("throughput_release node %p file %p\n", inode, file);
 
 	return 0;