Re: [libusb] My problem with URB_FUNCTION_GET_DESCRIPTOR_FROM_ENDPOINT

[Xiaofan C. <xia...@gm...>]

On Thu, Jun 13, 2013 at 3:41 PM, toannt <toa...@gm...> wrote:
> Hi all,
> I'm writing a sample application to simulate USB Transfers to USB Mini
> Pocket Airpen.
> I'm using the URBs capturing by USBLyzer application and libusb 1.0.9.

You should try out libusbx instead if you work under Windows.
libusb-1.0.9 release is broken under Windows.
http://sourceforge.net/projects/libusbx/files/releases/1.0.15/binaries/

> My problem is that: All URBs are simulated successfully except for 1 Control
> Transfer URB as below:
> The result of USBLyzer on Windows:
>
> /Sent package:
> USBPDO-1 - usbehci:
>  Request: get descriptor from endpoint. (code 0x24 on Windows).
>  Request Details: report.
>  I/O: in.
>  URB details:
>   Reserved 1: 0000h.
>   Index: 00h.
>   Descriptor type: 22h.
>   LanguageId: 0001h.
>   Reserved 2: 0000h.
>  Length: 64h.
>
> Respond package:
> Usbehci - USBPDO-1:
>  URB details:
>   Setup package:
>    bmRequestType: 82h
>    bRequest: 06h.
>    wValue: 2200h.
>    wIndex: 0001h.
>    wLength: 0064h.
> return actual length: 24h./

Just guessing here, could it be that bmRequestType is not really
0x82h but rather 0x81h, then it is a standard HID class
request to get the report descriptor.

Ref:
http://people.redhat.com/zaitcev/notes/usb_stern_cheat.txt
http://www.usb.org/developers/devclass_docs/HID1_11.pdf


-- 
Xiaofan