Re: [Libusb-devel] usb_bulk_msg

[Johannes E. <joh...@er...>]

On Thu, Mar 18, 2004, martin f krafft <ma...@ma...> wrote:
> I have taken upon me the task of converting a kernel module driver
> to a user-space library atop of libusb. Unfortunately I only have
> the kernel module source code, but zero support from manufacturer.
> 
> I am trying to write to the device. In the kernel module, this is
> done like so:
> 
>   usb_bulk_msg(dev, usb_sndbulkpipe(dev, 2), buf, size, &len, 2000);
> 
> which expands to:
> 
>   usb_bulk_msg(dev, PIPE_BULK << 30 | dev->devnum << 8 | 2 << 15,
>     buf, size, &len, 2000);
> 
> when I tried to use libusb's usb_bulk_write like so:
> 
>   usb_bulk_write(dev_h, 2, &buf, size, 2000);
> 
> nothing happened, and USB didn't report an error.

Something has to happen. You have a timeout atleast.

Are you sure you want &buf and not just buf?

> I wonder what I am doing wrong. Or is there a different way to do
> what I want in libusb?
> 
> I'd really appreciate any help...

No, it looks correct to me.

JE