Commit 19b85b3b authored by Bjørn Mork's avatar Bjørn Mork Committed by Greg Kroah-Hartman
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USB: cdc-wdm: no need to fill the in request URB every time it's submitted 



Filling the same URB with the exact same data is pointless.  It can be filled
once and resubmitted.  And not doing buffer allocation and URB filling at the
same place only serves to hide size mismatch bugs

Signed-off-by: default avatarBjørn Mork <bjorn@mork.no>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0b238583

drivers/usb/class/cdc-wdm.c

+19 −20
Original line number Diff line number Diff line
@@ -159,11 +159,9 @@ static void wdm_int_callback(struct urb *urb) 
	int rv = 0;

	int status = urb->status;

	struct wdm_device *desc;

	struct usb_ctrlrequest *req;

	struct usb_cdc_notification *dr;



	desc = urb->context;

	req = desc->irq;

	dr = (struct usb_cdc_notification *)desc->sbuf;



	if (status) {
@@ -210,24 +208,6 @@ static void wdm_int_callback(struct urb *urb) 
		goto exit;

	}



	req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);

	req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;

	req->wValue = 0;

	req->wIndex = desc->inum;

	req->wLength = cpu_to_le16(desc->wMaxCommand);



	usb_fill_control_urb(

		desc->response,

		interface_to_usbdev(desc->intf),

		/* using common endpoint 0 */

		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),

		(unsigned char *)req,

		desc->inbuf,

		desc->wMaxCommand,

		wdm_in_callback,

		desc

	);

	desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	spin_lock(&desc->iuspin);

	clear_bit(WDM_READ, &desc->flags);

	set_bit(WDM_RESPONDING, &desc->flags);
@@ -734,6 +714,25 @@ next_desc: 
	);

	desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;



	desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);

	desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;

	desc->irq->wValue = 0;

	desc->irq->wIndex = desc->inum;

	desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);



	usb_fill_control_urb(

		desc->response,

		interface_to_usbdev(desc->intf),

		/* using common endpoint 0 */

		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),

		(unsigned char *)desc->irq,

		desc->inbuf,

		desc->wMaxCommand,

		wdm_in_callback,

		desc

	);

	desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;



	usb_set_intfdata(intf, desc);

	rv = usb_register_dev(intf, &wdm_class);

	if (rv < 0)

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