usb: gadget: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[e-mail]>
Link: https://lore.kernel.org/r/20200707171500.GA13620@embeddedor
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/composite.c

···
 		descriptors = f->ssp_descriptors;
 		if (descriptors)
 			break;
-		/* FALLTHROUGH */
+		fallthrough;
 	case USB_SPEED_SUPER:
 		descriptors = f->ss_descriptors;
 		if (descriptors)
 			break;
-		/* FALLTHROUGH */
+		fallthrough;
 	case USB_SPEED_HIGH:
 		descriptors = f->hs_descriptors;
 		if (descriptors)
 			break;
-		/* FALLTHROUGH */
+		fallthrough;
 	default:
 		descriptors = f->fs_descriptors;
 	}
···
 			want_comp_desc = 1;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case USB_SPEED_SUPER:
 		if (gadget_is_superspeed(g)) {
 			speed_desc = f->ss_descriptors;
 			want_comp_desc = 1;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case USB_SPEED_HIGH:
 		if (gadget_is_dualspeed(g)) {
 			speed_desc = f->hs_descriptors;
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	default:
 		speed_desc = f->fs_descriptors;
 	}
···
 		case USB_ENDPOINT_XFER_ISOC:
 			/* mult: bits 1:0 of bmAttributes */
 			_ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
-			/* fall through */
+			fallthrough;
 		case USB_ENDPOINT_XFER_BULK:
 		case USB_ENDPOINT_XFER_INT:
 			_ep->maxburst = comp_desc->bMaxBurst + 1;
···
 			if (!gadget_is_dualspeed(gadget) ||
 			    gadget->speed >= USB_SPEED_SUPER)
 				break;
-			/* FALLTHROUGH */
+			fallthrough;
 		case USB_DT_CONFIG:
 			value = config_desc(cdev, w_value);
 			if (value >= 0)

drivers/usb/gadget/function/f_fs.c

···
 	switch (type) {
 	case FUNCTIONFS_RESUME:
 		rem_type2 = FUNCTIONFS_SUSPEND;
-		/* FALL THROUGH */
+		fallthrough;
 	case FUNCTIONFS_SUSPEND:
 	case FUNCTIONFS_SETUP:
 		rem_type1 = type;

drivers/usb/gadget/function/f_hid.c

···
 		break;
 	default:
 		ERROR(cdev, "Set report failed %d\n", req->status);
-		/* FALLTHROUGH */
+		fallthrough;
 	case -ECONNABORTED:		/* hardware forced ep reset */
 	case -ECONNRESET:		/* request dequeued */
 	case -ESHUTDOWN:		/* disconnect from host */

drivers/usb/gadget/function/f_mass_storage.c

···
 	case RELEASE:
 	case RESERVE:
 	case SEND_DIAGNOSTIC:
-		/* Fall through */
+		fallthrough;
 
 	default:
 unknown_cmnd:

drivers/usb/gadget/function/f_phonet.c

···
 	case -ESHUTDOWN: /* disconnected */
 	case -ECONNRESET: /* disabled */
 		dev->stats.tx_aborted_errors++;
-		/* fall through */
+		fallthrough;
 	default:
 		dev->stats.tx_errors++;
 	}
···
 	/* Do resubmit in these cases: */
 	case -EOVERFLOW: /* request buffer overflow */
 		dev->stats.rx_over_errors++;
-		/* fall through */
+		fallthrough;
 	default:
 		dev->stats.rx_errors++;
 		break;

drivers/usb/gadget/function/f_printer.c

···
 
 	/* data overrun */
 	case -EOVERFLOW:
-		/* FALLTHROUGH */
+		fallthrough;
 
 	default:
 		DBG(dev, "rx status %d\n", status);
···
 	switch (req->status) {
 	default:
 		VDBG(dev, "tx err %d\n", req->status);
-		/* FALLTHROUGH */
+		fallthrough;
 	case -ECONNRESET:		/* unlink */
 	case -ESHUTDOWN:		/* disconnect etc */
 		break;
···
 		if (!w_value && !w_length &&
 		   !(USB_DIR_IN & ctrl->bRequestType))
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return false;
 	}

drivers/usb/gadget/function/f_rndis.c

···
 		DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 			ep->name, status,
 			req->actual, req->length);
-		/* FALLTHROUGH */
+		fallthrough;
 	case 0:
 		if (ep != rndis->notify)
 			break;

drivers/usb/gadget/function/f_tcm.c

···
 	default:
 		pr_debug_once("Unsupported prio_attr: %02x.\n",
 				cmd_iu->prio_attr);
-		/* fall through */
+		fallthrough;
 	case UAS_SIMPLE_TAG:
 		cmd->prio_attr = TCM_SIMPLE_TAG;
 		break;

drivers/usb/gadget/function/u_ether.c

···
 	/* data overrun */
 	case -EOVERFLOW:
 		dev->net->stats.rx_over_errors++;
-		/* FALLTHROUGH */
+		fallthrough;
 
 	default:
 		dev->net->stats.rx_errors++;
···
 	default:
 		dev->net->stats.tx_errors++;
 		VDBG(dev, "tx err %d\n", req->status);
-		/* FALLTHROUGH */
+		fallthrough;
 	case -ECONNRESET:		/* unlink */
 	case -ESHUTDOWN:		/* disconnect etc */
 		dev_kfree_skb_any(skb);

drivers/usb/gadget/function/u_serial.c

···
 			/* presumably a transient fault */
 			pr_warn("ttyGS%d: unexpected RX status %d\n",
 				port->port_num, req->status);
-			/* FALLTHROUGH */
+			fallthrough;
 		case 0:
 			/* normal completion */
 			break;
···
 		/* presumably a transient fault */
 		pr_warn("%s: unexpected %s status %d\n",
 			__func__, ep->name, req->status);
-		/* FALL THROUGH */
+		fallthrough;
 	case 0:
 		/* normal completion */
 		gs_start_tx(port);
···
 	default:
 		pr_warn("%s: unexpected %s status %d\n",
 			__func__, ep->name, req->status);
-		/* fall through */
+		fallthrough;
 	case 0:
 		/* normal completion */
 		spin_lock(&cons->lock);

drivers/usb/gadget/legacy/inode.c

···
 	case STATE_EP_READY:			/* not configured yet */
 		if (is_write)
 			return 0;
-		// FALLTHRU
+		fallthrough;
 	case STATE_EP_UNBOUND:			/* clean disconnect */
 		break;
 	// case STATE_EP_DISABLED:		/* "can't happen" */
···
 	case GADGETFS_DISCONNECT:
 		if (dev->state == STATE_DEV_SETUP)
 			dev->setup_abort = 1;
-		// FALL THROUGH
+		fallthrough;
 	case GADGETFS_CONNECT:
 		dev->ev_next = 0;
 		break;
···
 			make_qualifier (dev);
 			break;
 		case USB_DT_OTHER_SPEED_CONFIG:
-			// FALLTHROUGH
 		case USB_DT_CONFIG:
 			value = config_buf (dev,
 					w_value >> 8,
···
 	case STATE_DEV_UNCONNECTED:
 		next_event (dev, GADGETFS_SUSPEND);
 		ep0_readable (dev);
-		/* FALLTHROUGH */
+		fallthrough;
 	default:
 		break;
 	}

drivers/usb/gadget/udc/dummy_hcd.c

···
 			if (max <= 1024)
 				break;
 			/* save a return statement */
-			/* fall through */
+			fallthrough;
 		case USB_SPEED_FULL:
 			if (max <= 64)
 				break;
 			/* save a return statement */
-			/* fall through */
+			fallthrough;
 		default:
 			if (max <= 8)
 				break;
···
 			if (max <= 1024)
 				break;
 			/* save a return statement */
-			/* fall through */
+			fallthrough;
 		case USB_SPEED_FULL:
 			if (max <= 1023)
 				break;
···
 			 * this almost certainly polls too fast.
 			 */
 			limit = max(limit, periodic_bytes(dum, ep));
-			/* FALLTHROUGH */
+			fallthrough;
 
 		default:
 treat_control_like_bulk:
···
 					 "supported for USB 2.0 roothub\n");
 				goto error;
 			}
-			/* FALLS THROUGH */
+			fallthrough;
 		case USB_PORT_FEAT_RESET:
 			/* if it's already enabled, disable */
 			if (hcd->speed == HCD_USB3) {
···
 			 * interval? Is it still 50msec as for HS?
 			 */
 			dum_hcd->re_timeout = jiffies + msecs_to_jiffies(50);
-			/* FALLS THROUGH */
+			fallthrough;
 		default:
 			if (hcd->speed == HCD_USB3) {
 				if ((dum_hcd->port_status &

drivers/usb/gadget/udc/goku_udc.c

···
 	max = get_unaligned_le16(&desc->wMaxPacketSize);
 	switch (max) {
 	case 64:
-		mode++; /* fall through */
+		mode++;
+		fallthrough;
 	case 32:
-		mode++; /* fall through */
+		mode++;
+		fallthrough;
 	case 16:
-		mode++; /* fall through */
+		mode++;
+		fallthrough;
 	case 8:
 		mode <<= 3;
 		break;

drivers/usb/gadget/udc/omap_udc.c

···
 				type = "integrated";
 				break;
 			}
-			/* FALL THROUGH */
+			fallthrough;
 		case 3:
 		case 11:
 		case 16:
···
 		case 14:			/* transceiverless */
 			if (cpu_is_omap1710())
 				goto bad_on_1710;
-			/* FALL THROUGH */
+			fallthrough;
 		case 13:
 		case 15:
 			type = "no";

drivers/usb/gadget/udc/s3c2410_udc.c

···
 	switch (idx) {
 	default:
 		idx = 0;
-		/* fall through */
+		fallthrough;
 	case 0:
 		fifo_reg = S3C2410_UDC_EP0_FIFO_REG;
 		break;
···
 	switch (idx) {
 	default:
 		idx = 0;
-		/* fall through */
+		fallthrough;
 	case 0:
 		fifo_reg = S3C2410_UDC_EP0_FIFO_REG;
 		break;

drivers/usb/gadget/udc/tegra-xudc.c

···
 		ep_wait_for_stopped(xudc, ep_index);
 		ep->enq_ptr = ep->deq_ptr;
 		tegra_xudc_ep_nuke(ep, -EIO);
-		/* FALLTHROUGH */
+		fallthrough;
 	case TRB_CMPL_CODE_STREAM_NUMP_ERROR:
 	case TRB_CMPL_CODE_CTRL_DIR_ERR:
 	case TRB_CMPL_CODE_INVALID_STREAM_TYPE_ERR: