Merge "USB: f_fs: Fix disconnect check during ongoing IO"

drivers/usb/gadget/f_fs.c

@@ -876,13 +876,21 @@ static ssize_t ffs_epfile_io(struct file *file,
 			ret = -EIO;
 		} else if (unlikely(wait_for_completion_interruptible(&done))) {
 			spin_lock_irq(&epfile->ffs->eps_lock);
-			if (ep->ep)
+			/*
+			 * While we were acquiring lock endpoint got disabled
+			 * (disconnect) or changed (composition switch) ?
+			 */
+			if (epfile->ep == ep)
 				usb_ep_dequeue(ep->ep, req);
 			spin_unlock_irq(&epfile->ffs->eps_lock);
 			ret = -EINTR;
 		} else {
 			spin_lock_irq(&epfile->ffs->eps_lock);
-			if (ep->ep)
+			/*
+			 * While we were acquiring lock endpoint got disabled
+			 * (disconnect) or changed (composition switch) ?
+			 */
+			if (epfile->ep == ep)
 				ret = ep->status;
 			else
 				ret = -ENODEV;
@@ -1561,6 +1569,7 @@ static void ffs_func_free(struct ffs_function *func)
 		if (ep->ep && ep->req)
 			usb_ep_free_request(ep->ep, ep->req);
 		ep->req = NULL;
+		ep->ep = NULL;
 		++ep;
 	} while (--count);
 	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);