---

yaml
---
r: 366620
b: refs/heads/master
c: 6a28bd9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 773adad14135999380a4652b4ba01c5694827870
+refs/heads/master: 6a28bd94f4d068b6de65517e52f52b6840603d0a

trunk/drivers/media/common/siano/smsdvb-debugfs.c

@@ -352,6 +352,14 @@ static int smsdvb_stats_open(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static void smsdvb_debugfs_data_release(struct kref *ref)
+{
+	struct smsdvb_debugfs *debug_data;
+
+	debug_data = container_of(ref, struct smsdvb_debugfs, refcount);
+	kfree(debug_data);
+}
+
 static int smsdvb_stats_wait_read(struct smsdvb_debugfs *debug_data)
 {
 	int rc = 1;
@@ -368,41 +376,73 @@ static int smsdvb_stats_wait_read(struct smsdvb_debugfs *debug_data)
 	return rc;
 }
 
-static ssize_t smsdvb_stats_read(struct file *file, char __user *user_buf,
-				      size_t nbytes, loff_t *ppos)
+static unsigned int smsdvb_stats_poll(struct file *file, poll_table *wait)
 {
-	int rc = 0;
 	struct smsdvb_debugfs *debug_data = file->private_data;
+	int rc;
 
-	rc = wait_event_interruptible(debug_data->stats_queue,
-				      smsdvb_stats_wait_read(debug_data));
-	if (rc < 0)
-		return rc;
+	kref_get(&debug_data->refcount);
 
-	rc = simple_read_from_buffer(user_buf, nbytes, ppos,
-				     debug_data->stats_data,
-				     debug_data->stats_count);
-	spin_lock(&debug_data->lock);
-	debug_data->stats_was_read = true;
-	spin_unlock(&debug_data->lock);
+	poll_wait(file, &debug_data->stats_queue, wait);
+
+	rc = smsdvb_stats_wait_read(debug_data);
+	if (rc > 0)
+		rc = POLLIN | POLLRDNORM;
+
+	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
 
 	return rc;
 }
 
-static void smsdvb_debugfs_data_release(struct kref *ref)
+static ssize_t smsdvb_stats_read(struct file *file, char __user *user_buf,
+				      size_t nbytes, loff_t *ppos)
 {
-	struct smsdvb_debugfs *debug_data;
+	int rc = 0, len;
+	struct smsdvb_debugfs *debug_data = file->private_data;
 
-	debug_data = container_of(ref, struct smsdvb_debugfs, refcount);
-	kfree(debug_data);
+	kref_get(&debug_data->refcount);
+
+	if (file->f_flags & O_NONBLOCK) {
+		rc = smsdvb_stats_wait_read(debug_data);
+		if (!rc) {
+			rc = -EWOULDBLOCK;
+			goto ret;
+		}
+	} else {
+		rc = wait_event_interruptible(debug_data->stats_queue,
+				      smsdvb_stats_wait_read(debug_data));
+		if (rc < 0)
+			goto ret;
+	}
+
+	if (debug_data->stats_was_read) {
+		rc = 0;	/* EOF */
+		goto ret;
+	}
+
+	len = debug_data->stats_count - *ppos;
+	if (len >= 0)
+		rc = simple_read_from_buffer(user_buf, nbytes, ppos,
+					     debug_data->stats_data, len);
+	else
+		rc = 0;
+
+	if (*ppos >= debug_data->stats_count) {
+		spin_lock(&debug_data->lock);
+		debug_data->stats_was_read = true;
+		spin_unlock(&debug_data->lock);
+	}
+ret:
+	kref_put(&debug_data->refcount, smsdvb_debugfs_data_release);
+	return rc;
 }
 
 static int smsdvb_stats_release(struct inode *inode, struct file *file)
 {
 	struct smsdvb_debugfs *debug_data = file->private_data;
 
 	spin_lock(&debug_data->lock);
-	debug_data->stats_was_read = true;
+	debug_data->stats_was_read = true;	/* return EOF to read() */
 	spin_unlock(&debug_data->lock);
 	wake_up_interruptible_sync(&debug_data->stats_queue);
 
@@ -414,6 +454,7 @@ static int smsdvb_stats_release(struct inode *inode, struct file *file)
 
 static const struct file_operations debugfs_stats_ops = {
 	.open = smsdvb_stats_open,
+	.poll = smsdvb_stats_poll,
 	.read = smsdvb_stats_read,
 	.release = smsdvb_stats_release,
 	.llseek = generic_file_llseek,