input: Always wait for hid request completion in hiddev before returning

       to the caller process.

drivers/usb/input/hid.h

@@ -448,6 +448,7 @@ int hid_set_field(struct hid_field *, unsigned, __s32);
 void hid_submit_report(struct hid_device *, struct hid_report *, unsigned char dir);
 void hid_init_reports(struct hid_device *hid);
 int hid_find_report_by_usage(struct hid_device *hid, __u32 wanted_usage, struct hid_report **report, int type);
+int hid_wait_io(struct hid_device* hid);
 
 
 #ifdef CONFIG_HID_FF

drivers/usb/input/hiddev.c

@@ -509,6 +509,7 @@ static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd
 			return -EINVAL;
 
 		hid_submit_report(hid, report, USB_DIR_IN);
+		hid_wait_io(hid);
 
 		return 0;