usb: gadget: add "maxpacket_limit" field to struct usb_ep

This patch adds "maxpacket_limit" to struct usb_ep. This field contains
maximum value of maxpacket supported by driver, and is set in driver probe.
This value should be used by autoconfig() function, because value of field
"maxpacket" is set to value from endpoint descriptor when endpoint becomes
enabled. So when autoconfig() function will be called again for this endpoint,
"maxpacket" value will contain wMaxPacketSize from descriptior instead of
maximum packet size for this endpoint.

For this reason this patch adds new field "maxpacket_limit" which contains
value of maximum packet size (which defines maximum endpoint capabilities).
This value is used in ep_matches() function used by autoconfig().

Value of "maxpacket_limit" should be set in UDC driver probe function, using
usb_ep_set_maxpacket_limit() function, defined in gadget.h. This function
set choosen value to both "maxpacket_limit" and "maxpacket" fields.

This patch modifies UDC drivers by adding support for maxpacket_limit.

Signed-off-by: Robert Baldyga <[e-mail]>
Signed-off-by: Kyungmin Park <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/chipidea/udc.c

···
 			 * eps, maxP is set by epautoconfig() called
 			 * by gadget layer
 			 */
-			hwep->ep.maxpacket = (unsigned short)~0;
+			usb_ep_set_maxpacket_limit(&hwep->ep, (unsigned short)~0);
 
 			INIT_LIST_HEAD(&hwep->qh.queue);
 			hwep->qh.ptr = dma_pool_alloc(ci->qh_pool, GFP_KERNEL,
···
 				else
 					ci->ep0in = hwep;
 
-				hwep->ep.maxpacket = CTRL_PAYLOAD_MAX;
+				usb_ep_set_maxpacket_limit(&hwep->ep, CTRL_PAYLOAD_MAX);
 				continue;
 			}
 

drivers/usb/dwc3/gadget.c

···
 		dev_vdbg(dwc->dev, "initializing %s\n", dep->name);
 
 		if (epnum == 0 || epnum == 1) {
-			dep->endpoint.maxpacket = 512;
+			usb_ep_set_maxpacket_limit(&dep->endpoint, 512);
 			dep->endpoint.maxburst = 1;
 			dep->endpoint.ops = &dwc3_gadget_ep0_ops;
 			if (!epnum)
···
 		} else {
 			int		ret;
 
-			dep->endpoint.maxpacket = 1024;
+			usb_ep_set_maxpacket_limit(&dep->endpoint, 1024);
 			dep->endpoint.max_streams = 15;
 			dep->endpoint.ops = &dwc3_gadget_ep_ops;
 			list_add_tail(&dep->endpoint.ep_list,

drivers/usb/gadget/amd5536udc.c

···
 	ep->ep.ops = &udc_ep_ops;
 	INIT_LIST_HEAD(&ep->queue);
 
-	ep->ep.maxpacket = (u16) ~0;
+	usb_ep_set_maxpacket_limit(&ep->ep,(u16) ~0);
 	/* set NAK */
 	tmp = readl(&ep->regs->ctl);
 	tmp |= AMD_BIT(UDC_EPCTL_SNAK);
···
 	}
 	/* EP0 max packet */
 	if (dev->gadget.speed == USB_SPEED_FULL) {
-		dev->ep[UDC_EP0IN_IX].ep.maxpacket = UDC_FS_EP0IN_MAX_PKT_SIZE;
-		dev->ep[UDC_EP0OUT_IX].ep.maxpacket =
-						UDC_FS_EP0OUT_MAX_PKT_SIZE;
+		usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0IN_IX].ep,
+					   UDC_FS_EP0IN_MAX_PKT_SIZE);
+		usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0OUT_IX].ep,
+					   UDC_FS_EP0OUT_MAX_PKT_SIZE);
 	} else if (dev->gadget.speed == USB_SPEED_HIGH) {
-		dev->ep[UDC_EP0IN_IX].ep.maxpacket = UDC_EP0IN_MAX_PKT_SIZE;
-		dev->ep[UDC_EP0OUT_IX].ep.maxpacket = UDC_EP0OUT_MAX_PKT_SIZE;
+		usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0IN_IX].ep,
+					   UDC_EP0IN_MAX_PKT_SIZE);
+		usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0OUT_IX].ep,
+					   UDC_EP0OUT_MAX_PKT_SIZE);
 	}
 
 	/*

drivers/usb/gadget/at91_udc.c

···
 		ep->ep.desc = NULL;
 		ep->stopped = 0;
 		ep->fifo_bank = 0;
-		ep->ep.maxpacket = ep->maxpacket;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
 		ep->creg = (void __iomem *) udc->udp_baseaddr + AT91_UDP_CSR(i);
 		/* initialize one queue per endpoint */
 		INIT_LIST_HEAD(&ep->queue);
···
 
 	/* newer chips have more FIFO memory than rm9200 */
 	if (cpu_is_at91sam9260() || cpu_is_at91sam9g20()) {
-		udc->ep[0].maxpacket = 64;
-		udc->ep[3].maxpacket = 64;
-		udc->ep[4].maxpacket = 512;
-		udc->ep[5].maxpacket = 512;
+		usb_ep_set_maxpacket_limit(&udc->ep[0], 64);
+		usb_ep_set_maxpacket_limit(&udc->ep[3], 64);
+		usb_ep_set_maxpacket_limit(&udc->ep[4], 512);
+		usb_ep_set_maxpacket_limit(&udc->ep[5], 512);
 	} else if (cpu_is_at91sam9261() || cpu_is_at91sam9g10()) {
-		udc->ep[3].maxpacket = 64;
+		usb_ep_set_maxpacket_limit(&udc->ep[3], 64);
 	} else if (cpu_is_at91sam9263()) {
-		udc->ep[0].maxpacket = 64;
-		udc->ep[3].maxpacket = 64;
+		usb_ep_set_maxpacket_limit(&udc->ep[0], 64);
+		usb_ep_set_maxpacket_limit(&udc->ep[3], 64);
 	}
 
 	udc->udp_baseaddr = ioremap(res->start, resource_size(res));

drivers/usb/gadget/atmel_usba_udc.c

···
 		ep->dma_regs = udc->regs + USBA_DMA_BASE(i);
 		ep->fifo = udc->fifo + USBA_FIFO_BASE(i);
 		ep->ep.ops = &usba_ep_ops;
-		ep->ep.maxpacket = ep->fifo_size;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->fifo_size);
 		ep->udc = udc;
 		INIT_LIST_HEAD(&ep->queue);
 
···
 		ep->fifo = udc->fifo + USBA_FIFO_BASE(i);
 		ep->ep.ops = &usba_ep_ops;
 		ep->ep.name = pdata->ep[i].name;
-		ep->fifo_size = ep->ep.maxpacket = pdata->ep[i].fifo_size;
+		ep->fifo_size = pdata->ep[i].fifo_size;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->fifo_size);
 		ep->udc = udc;
 		INIT_LIST_HEAD(&ep->queue);
 		ep->nr_banks = pdata->ep[i].nr_banks;

drivers/usb/gadget/bcm63xx_udc.c

···
 
 		if (idx < 0)
 			continue;
-		udc->bep[idx].ep.maxpacket = max_pkt;
+		usb_ep_set_maxpacket_limit(&udc->bep[idx].ep, max_pkt);
 
 		val = (idx << USBD_CSR_EP_LOG_SHIFT) |
 		      (cfg->dir << USBD_CSR_EP_DIR_SHIFT) |
···
 		bep->ep.ops = &bcm63xx_udc_ep_ops;
 		list_add_tail(&bep->ep.ep_list, &udc->gadget.ep_list);
 		bep->halted = 0;
-		bep->ep.maxpacket = BCM63XX_MAX_CTRL_PKT;
+		usb_ep_set_maxpacket_limit(&bep->ep, BCM63XX_MAX_CTRL_PKT);
 		bep->udc = udc;
 		bep->ep.desc = NULL;
 		INIT_LIST_HEAD(&bep->queue);

drivers/usb/gadget/dummy_hcd.c

···
 		list_add_tail(&ep->ep.ep_list, &dum->gadget.ep_list);
 		ep->halted = ep->wedged = ep->already_seen =
 				ep->setup_stage = 0;
-		ep->ep.maxpacket = ~0;
+		usb_ep_set_maxpacket_limit(&ep->ep, ~0);
 		ep->ep.max_streams = 16;
 		ep->last_io = jiffies;
 		ep->gadget = &dum->gadget;

drivers/usb/gadget/epautoconf.c

···
 	 * and wants to know the maximum possible, provide the info.
 	 */
 	if (desc->wMaxPacketSize == 0)
-		desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket);
+		desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket_limit);
 
 	/* endpoint maxpacket size is an input parameter, except for bulk
 	 * where it's an output parameter representing the full speed limit.
···
 
 	case USB_ENDPOINT_XFER_ISOC:
 		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
-		if (ep->maxpacket < max)
+		if (ep->maxpacket_limit < max)
 			return 0;
 		if (!gadget_is_dualspeed(gadget) && max > 1023)
 			return 0;
···
 
 	/* report (variable) full speed bulk maxpacket */
 	if ((USB_ENDPOINT_XFER_BULK == type) && !ep_comp) {
-		int size = ep->maxpacket;
+		int size = ep->maxpacket_limit;
 
 		/* min() doesn't work on bitfields with gcc-3.5 */
 		if (size > 64)

drivers/usb/gadget/fotg210-udc.c

···
 		INIT_LIST_HEAD(&ep->queue);
 		ep->ep.name = fotg210_ep_name[i];
 		ep->ep.ops = &fotg210_ep_ops;
+		usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
 	}
-	fotg210->ep[0]->ep.maxpacket = 0x40;
+	usb_ep_set_maxpacket_limit(&fotg210->ep[0]->ep, 0x40);
 	fotg210->gadget.ep0 = &fotg210->ep[0]->ep;
 	INIT_LIST_HEAD(&fotg210->gadget.ep0->ep_list);
 

drivers/usb/gadget/fsl_qe_udc.c

···
 
 	ep->ep.ops = &qe_ep_ops;
 	ep->stopped = 1;
-	ep->ep.maxpacket = (unsigned short) ~0;
+	usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
 	ep->ep.desc = NULL;
 	ep->dir = 0xff;
 	ep->epnum = (u8)pipe_num;

drivers/usb/gadget/fsl_udc_core.c

···
 	/* for ep0: maxP defined in desc
 	 * for other eps, maxP is set by epautoconfig() called by gadget layer
 	 */
-	ep->ep.maxpacket = (unsigned short) ~0;
+	usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
 
 	/* the queue lists any req for this ep */
 	INIT_LIST_HEAD(&ep->queue);
···
 	 * for other eps, gadget layer called ep_enable with defined desc
 	 */
 	udc_controller->eps[0].ep.desc = &fsl_ep0_desc;
-	udc_controller->eps[0].ep.maxpacket = USB_MAX_CTRL_PAYLOAD;
+	usb_ep_set_maxpacket_limit(&udc_controller->eps[0].ep,
+				   USB_MAX_CTRL_PAYLOAD);
 
 	/* setup the udc->eps[] for non-control endpoints and link
 	 * to gadget.ep_list */

drivers/usb/gadget/fusb300_udc.c

···
 		INIT_LIST_HEAD(&ep->queue);
 		ep->ep.name = fusb300_ep_name[i];
 		ep->ep.ops = &fusb300_ep_ops;
-		ep->ep.maxpacket = HS_BULK_MAX_PACKET_SIZE;
+		usb_ep_set_maxpacket_limit(&ep->ep, HS_BULK_MAX_PACKET_SIZE);
 	}
-	fusb300->ep[0]->ep.maxpacket = HS_CTL_MAX_PACKET_SIZE;
+	usb_ep_set_maxpacket_limit(&fusb300->ep[0]->ep, HS_CTL_MAX_PACKET_SIZE);
 	fusb300->ep[0]->epnum = 0;
 	fusb300->gadget.ep0 = &fusb300->ep[0]->ep;
 	INIT_LIST_HEAD(&fusb300->gadget.ep0->ep_list);

drivers/usb/gadget/goku_udc.c

···
 		}
 	}
 
-	ep->ep.maxpacket = MAX_FIFO_SIZE;
+	usb_ep_set_maxpacket_limit(&ep->ep, MAX_FIFO_SIZE);
 	ep->ep.desc = NULL;
 	ep->stopped = 1;
 	ep->irqs = 0;
···
 	}
 
 	dev->ep[0].reg_mode = NULL;
-	dev->ep[0].ep.maxpacket = MAX_EP0_SIZE;
+	usb_ep_set_maxpacket_limit(&dev->ep[0].ep, MAX_EP0_SIZE);
 	list_del_init (&dev->ep[0].ep.ep_list);
 }
 

drivers/usb/gadget/lpc32xx_udc.c

···
 
 		if (i != 0)
 			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
-		ep->ep.maxpacket = ep->maxpacket;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
 		INIT_LIST_HEAD(&ep->queue);
 		ep->req_pending = 0;
 	}

drivers/usb/gadget/m66592-udc.c

···
 		INIT_LIST_HEAD(&ep->queue);
 		ep->ep.name = m66592_ep_name[i];
 		ep->ep.ops = &m66592_ep_ops;
-		ep->ep.maxpacket = 512;
+		usb_ep_set_maxpacket_limit(&ep->ep, 512);
 	}
-	m66592->ep[0].ep.maxpacket = 64;
+	usb_ep_set_maxpacket_limit(&m66592->ep[0].ep, 64);
 	m66592->ep[0].pipenum = 0;
 	m66592->ep[0].fifoaddr = M66592_CFIFO;
 	m66592->ep[0].fifosel = M66592_CFIFOSEL;

drivers/usb/gadget/mv_u3d_core.c

···
 	ep->ep.name = ep->name;
 	ep->ep.ops = &mv_u3d_ep_ops;
 	ep->wedge = 0;
-	ep->ep.maxpacket = MV_U3D_EP0_MAX_PKT_SIZE;
+	usb_ep_set_maxpacket_limit(&ep->ep, MV_U3D_EP0_MAX_PKT_SIZE);
 	ep->ep_num = 0;
 	ep->ep.desc = &mv_u3d_ep0_desc;
 	INIT_LIST_HEAD(&ep->queue);
···
 		ep->ep.name = ep->name;
 
 		ep->ep.ops = &mv_u3d_ep_ops;
-		ep->ep.maxpacket = (unsigned short) ~0;
+		usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
 		ep->ep_num = i / 2;
 
 		INIT_LIST_HEAD(&ep->queue);

drivers/usb/gadget/mv_udc_core.c

···
 	ep->ep.ops = &mv_ep_ops;
 	ep->wedge = 0;
 	ep->stopped = 0;
-	ep->ep.maxpacket = EP0_MAX_PKT_SIZE;
+	usb_ep_set_maxpacket_limit(&ep->ep, EP0_MAX_PKT_SIZE);
 	ep->ep_num = 0;
 	ep->ep.desc = &mv_ep0_desc;
 	INIT_LIST_HEAD(&ep->queue);
···
 
 		ep->ep.ops = &mv_ep_ops;
 		ep->stopped = 0;
-		ep->ep.maxpacket = (unsigned short) ~0;
+		usb_ep_set_maxpacket_limit(&ep->ep, (unsigned short) ~0);
 		ep->ep_num = i / 2;
 
 		INIT_LIST_HEAD(&ep->queue);

drivers/usb/gadget/net2272.c

···
 	ep->desc = NULL;
 	INIT_LIST_HEAD(&ep->queue);
 
-	ep->ep.maxpacket = ~0;
+	usb_ep_set_maxpacket_limit(&ep->ep, ~0);
 	ep->ep.ops = &net2272_ep_ops;
 
 	/* disable irqs, endpoint */
···
 			ep->fifo_size = 64;
 		net2272_ep_reset(ep);
 	}
-	dev->ep[0].ep.maxpacket = 64;
+	usb_ep_set_maxpacket_limit(&dev->ep[0].ep, 64);
 
 	dev->gadget.ep0 = &dev->ep[0].ep;
 	dev->ep[0].stopped = 0;

drivers/usb/gadget/net2280.c

···
 	ep->desc = NULL;
 	INIT_LIST_HEAD (&ep->queue);
 
-	ep->ep.maxpacket = ~0;
+	usb_ep_set_maxpacket_limit(&ep->ep, ~0);
 	ep->ep.ops = &net2280_ep_ops;
 
 	/* disable the dma, irqs, endpoint... */
···
 		ep->regs = &dev->epregs [tmp];
 		ep_reset (dev->regs, ep);
 	}
-	dev->ep [0].ep.maxpacket = 64;
-	dev->ep [5].ep.maxpacket = 64;
-	dev->ep [6].ep.maxpacket = 64;
+	usb_ep_set_maxpacket_limit(&dev->ep [0].ep, 64);
+	usb_ep_set_maxpacket_limit(&dev->ep [5].ep, 64);
+	usb_ep_set_maxpacket_limit(&dev->ep [6].ep, 64);
 
 	dev->gadget.ep0 = &dev->ep [0].ep;
 	dev->ep [0].stopped = 0;

drivers/usb/gadget/omap_udc.c

···
 
 	ep->ep.name = ep->name;
 	ep->ep.ops = &omap_ep_ops;
-	ep->ep.maxpacket = ep->maxpacket = maxp;
+	ep->maxpacket = maxp;
+	usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
 	list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
 
 	return buf;

drivers/usb/gadget/pch_udc.c

···
 			ep->offset_addr = (UDC_EPINT_OUT_SHIFT + ep->num) *
 					  UDC_EP_REG_SHIFT;
 		/* need to set ep->ep.maxpacket and set Default Configuration?*/
-		ep->ep.maxpacket = UDC_BULK_MAX_PKT_SIZE;
+		usb_ep_set_maxpacket_limit(&ep->ep, UDC_BULK_MAX_PKT_SIZE);
 		list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);
 		INIT_LIST_HEAD(&ep->queue);
 	}
-	dev->ep[UDC_EP0IN_IDX].ep.maxpacket = UDC_EP0IN_MAX_PKT_SIZE;
-	dev->ep[UDC_EP0OUT_IDX].ep.maxpacket = UDC_EP0OUT_MAX_PKT_SIZE;
+	usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0IN_IDX].ep, UDC_EP0IN_MAX_PKT_SIZE);
+	usb_ep_set_maxpacket_limit(&dev->ep[UDC_EP0OUT_IDX].ep, UDC_EP0OUT_MAX_PKT_SIZE);
 
 	/* remove ep0 in and out from the list.  They have own pointer */
 	list_del_init(&dev->ep[UDC_EP0IN_IDX].ep.ep_list);

drivers/usb/gadget/pxa25x_udc.c

···
 		ep->stopped = 0;
 		INIT_LIST_HEAD (&ep->queue);
 		ep->pio_irqs = 0;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->ep.maxpacket);
 	}
 
 	/* the rest was statically initialized, and is read-only */

drivers/usb/gadget/pxa27x_udc.c

···
 	}
 
 	/* USB endpoints init */
-	for (i = 1; i < NR_USB_ENDPOINTS; i++)
+	for (i = 1; i < NR_USB_ENDPOINTS; i++) {
 		list_add_tail(&dev->udc_usb_ep[i].usb_ep.ep_list,
 				&dev->gadget.ep_list);
+		usb_ep_set_maxpacket_limit(&dev->udc_usb_ep[i].usb_ep,
+					   dev->udc_usb_ep[i].usb_ep.maxpacket);
+	}
 }
 
 /**

drivers/usb/gadget/r8a66597-udc.c

···
 		INIT_LIST_HEAD(&ep->queue);
 		ep->ep.name = r8a66597_ep_name[i];
 		ep->ep.ops = &r8a66597_ep_ops;
-		ep->ep.maxpacket = 512;
+		usb_ep_set_maxpacket_limit(&ep->ep, 512);
 	}
-	r8a66597->ep[0].ep.maxpacket = 64;
+	usb_ep_set_maxpacket_limit(&r8a66597->ep[0].ep, 64);
 	r8a66597->ep[0].pipenum = 0;
 	r8a66597->ep[0].fifoaddr = CFIFO;
 	r8a66597->ep[0].fifosel = CFIFOSEL;

drivers/usb/gadget/s3c-hsotg.c

···
 
 	hs_ep->parent = hsotg;
 	hs_ep->ep.name = hs_ep->name;
-	hs_ep->ep.maxpacket = epnum ? 1024 : EP0_MPS_LIMIT;
+	usb_ep_set_maxpacket_limit(&hs_ep->ep, epnum ? 1024 : EP0_MPS_LIMIT);
 	hs_ep->ep.ops = &s3c_hsotg_ep_ops;
 
 	/*

drivers/usb/gadget/s3c-hsudc.c

···
 
 	hsep->dev = hsudc;
 	hsep->ep.name = hsep->name;
-	hsep->ep.maxpacket = epnum ? 512 : 64;
+	usb_ep_set_maxpacket_limit(&hsep->ep, epnum ? 512 : 64);
 	hsep->ep.ops = &s3c_hsudc_ep_ops;
 	hsep->fifo = hsudc->regs + S3C_BR(epnum);
 	hsep->ep.desc = NULL;

drivers/usb/gadget/s3c2410_udc.c

···
 		ep->ep.desc = NULL;
 		ep->halted = 0;
 		INIT_LIST_HEAD(&ep->queue);
+		usb_ep_set_maxpacket_limit(&ep->ep, &ep->ep.maxpacket);
 	}
 }
 

drivers/usb/musb/musb_gadget.c

···
 	ep->end_point.name = ep->name;
 	INIT_LIST_HEAD(&ep->end_point.ep_list);
 	if (!epnum) {
-		ep->end_point.maxpacket = 64;
+		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
 		ep->end_point.ops = &musb_g_ep0_ops;
 		musb->g.ep0 = &ep->end_point;
 	} else {
 		if (is_in)
-			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
+			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
 		else
-			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
+			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
 		ep->end_point.ops = &musb_ep_ops;
 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
 	}

drivers/usb/renesas_usbhs/mod_gadget.c

···
 		/* init DCP */
 		if (usbhsg_is_dcp(uep)) {
 			gpriv->gadget.ep0 = &uep->ep;
-			uep->ep.maxpacket = 64;
+			usb_ep_set_maxpacket_limit(&uep->ep, 64);
 		}
 		/* init normal pipe */
 		else {
-			uep->ep.maxpacket = 512;
+			usb_ep_set_maxpacket_limit(&uep->ep, 512);
 			list_add_tail(&uep->ep.ep_list, &gpriv->gadget.ep_list);
 		}
 	}

include/linux/usb/gadget.h

···
  * @maxpacket:The maximum packet size used on this endpoint.  The initial
  *	value can sometimes be reduced (hardware allowing), according to
  *      the endpoint descriptor used to configure the endpoint.
+ * @maxpacket_limit:The maximum packet size value which can be handled by this
+ *	endpoint. It's set once by UDC driver when endpoint is initialized, and
+ *	should not be changed. Should not be confused with maxpacket.
  * @max_streams: The maximum number of streams supported
  *	by this EP (0 - 16, actual number is 2^n)
  * @mult: multiplier, 'mult' value for SS Isoc EPs
···
 	const struct usb_ep_ops	*ops;
 	struct list_head	ep_list;
 	unsigned		maxpacket:16;
+	unsigned		maxpacket_limit:16;
 	unsigned		max_streams:16;
 	unsigned		mult:2;
 	unsigned		maxburst:5;
···
 };
 
 /*-------------------------------------------------------------------------*/
+
+/**
+ * usb_ep_set_maxpacket_limit - set maximum packet size limit for endpoint
+ * @ep:the endpoint being configured
+ * @maxpacket_limit:value of maximum packet size limit
+ *
+ * This function shoud be used only in UDC drivers to initialize endpoint
+ * (usually in probe function).
+ */
+static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
+					      unsigned maxpacket_limit)
+{
+	ep->maxpacket_limit = maxpacket_limit;
+	ep->maxpacket = maxpacket_limit;
+}
 
 /**
  * usb_ep_enable - configure endpoint, making it usable