--- zzzz-none-000/linux-4.4.271/drivers/mtd/ubi/cdev.c	2021-06-03 06:22:09.000000000 +0000
+++ hawkeye-5590-750/linux-4.4.271/drivers/mtd/ubi/cdev.c	2023-04-19 10:22:29.000000000 +0000
@@ -975,7 +975,7 @@
 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg)
 {
-	int err = 0;
+	int err = 0, force = 0;
 	void __user *argp = (void __user *)arg;
 
 	if (!capable(CAP_SYS_RESOURCE))
@@ -1025,6 +1025,10 @@
 	}
 
 	/* Detach an MTD device command */
+	case UBI_IOCFDET:
+		force = 1;
+		/* fallthrough */
+
 	case UBI_IOCDET:
 	{
 		int ubi_num;
@@ -1037,7 +1041,7 @@
 		}
 
 		mutex_lock(&ubi_devices_mutex);
-		err = ubi_detach_mtd_dev(ubi_num, 0);
+		err = ubi_detach_mtd_dev(ubi_num, force);
 		mutex_unlock(&ubi_devices_mutex);
 		break;
 	}