sync: add poll support

Change-Id: I294e481bba92658e6dd26f157ddbf0e9ff4ce8a5
Signed-off-by: Erik Gilling <konkers@android.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/base/sync.c b/drivers/base/sync.c
index 80749ec68b8..cc40e4c9e65 100644
--- a/drivers/base/sync.c
+++ b/drivers/base/sync.c
@@ -18,6 +18,7 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
+#include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
@@ -221,12 +222,14 @@ out:
 }
 
 static int sync_fence_release(struct inode *inode, struct file *file);
+static unsigned int sync_fence_poll(struct file *file, poll_table *wait);
 static long sync_fence_ioctl(struct file *file, unsigned int cmd,
 			     unsigned long arg);
 
 
 static const struct file_operations sync_fence_fops = {
 	.release = sync_fence_release,
+	.poll = sync_fence_poll,
 	.unlocked_ioctl = sync_fence_ioctl,
 };
 
@@ -497,6 +500,20 @@ static int sync_fence_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static unsigned int sync_fence_poll(struct file *file, poll_table *wait)
+{
+	struct sync_fence *fence = file->private_data;
+
+	poll_wait(file, &fence->wq, wait);
+
+	if (fence->status == 1)
+		return POLLIN;
+	else if (fence->status < 0)
+		return POLLERR;
+	else
+		return 0;
+}
+
 static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
 {
 	__u32 value;