[PATCH] tpm: read return code issue

Replace an erroneous return code for the read function when no data is
available.
Signed-of-by: NKylene Hall <kjhall@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/char/tpm/tpm.c

@@ -489,29 +489,19 @@ ssize_t tpm_read(struct file * file, char __user * buf,
 		 size_t size, loff_t * off)
 {
 	struct tpm_chip *chip = file->private_data;
-	int ret_size = -ENODATA;
+	int ret_size;
 
-	if (atomic_read(&chip->data_pending) != 0) {	/* Result available */
-		down(&chip->timer_manipulation_mutex);
-		del_singleshot_timer_sync(&chip->user_read_timer);
-		up(&chip->timer_manipulation_mutex);
+	del_singleshot_timer_sync(&chip->user_read_timer);
+	ret_size = atomic_read(&chip->data_pending);
+	atomic_set(&chip->data_pending, 0);
+	if (ret_size > 0) {	/* relay data */
+		if (size < ret_size)
+			ret_size = size;
 
 		down(&chip->buffer_mutex);
-
-		ret_size = atomic_read(&chip->data_pending);
-		atomic_set(&chip->data_pending, 0);
-
-		if (ret_size == 0)	/* timeout just occurred */
-			ret_size = -ETIME;
-		else if (ret_size > 0) {	/* relay data */
-			if (size < ret_size)
-				ret_size = size;
-
-			if (copy_to_user((void __user *) buf,
-					 chip->data_buffer, ret_size)) {
-				ret_size = -EFAULT;
-			}
-		}
+		if (copy_to_user
+		    ((void __user *) buf, chip->data_buffer, ret_size))
+			ret_size = -EFAULT;
 		up(&chip->buffer_mutex);
 	}