On Thu, 8 Feb 2007, Pandita, Vikram wrote:
> While sending the string descriptor, Gadget Zero does not send a ZLP in
> case the packet size is maxpacket size, resulting in a USBCV failure.
Not correct. Gadget Zero _does_ send a ZLP if the packet size is equal to
the maxpacket size, provided the host requested a longer response.
Conversely, if the host asked for exactly maxpacket bytes and the gadget
sends back a response of that length, then there should not be a ZLP
added.
> The Ethernet Gadget has the following code which is missing from Gadget
> Zero. Should this be added to the Gadget Zero also?
It isn't needed in either driver, although it doesn't hurt. The device
controller driver will always check for (value % gadget->ep0->maxpacket)
== 0 before sending the ZLP, so the gadget driver doesn't need to check.
> --- a/drivers/usb/gadget/zero.c 2007-02-02 18:33:34.000000000 +0530
> +++ b/drivers/usb/gadget/zero.c 2007-02-07 17:28:47.000000000 +0530
> @@ -1072,7 +1072,8 @@ unknown:
> /* respond with data transfer before status phase? */
> if (value >= 0) {
> req->length = value;
> - req->zero = value < w_length;
> + req->zero = value < w_length &&
> + (value % gadget->ep0->maxpacket) == 0;
> value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
> if (value < 0) {
> DBG (dev, "ep_queue --> %d\n", value);
Alan Stern
-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier.
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
linux-usb-devel@lists.sourceforge.net
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
