Re: [Libusb-devel] USB error: could not get bound driver: No data available

[Tim R. <ti...@pr...>]

Jakov wrote:
>
>
>     yes, I just use VM for testing. And as I know, the latest VMWare
>     supports 2.0 already.
>

That's not how I read it.  What I read says that it supports USB 2.0 
devices on the host, but that it only supports USB 1.1 devices in the guest.


>     The last time, when the system down, some errors on enumeration
>     may occur. I don't understand yet the progress of detecting and
>     assigning USB interface so ... it's bit difficult for me.
>


>     Just a strange thing that lsusb can list this USB device while
>     "usb_get_driver_np" can't. Is it a standard function, or a libusb
>     function? Could you tell me more about "You don't need to
>     disconnect the standard driver, because there isn't one.  You just
>     start using it."
>

There are no "standard functions" for USB; everything you are using is 
libusb.

It's not a strange thing at all.  "usb_get_driver_np" doesn't list 
devices.  What it does is ask this question: "have any of the standard 
kernel drivers claimed this device?"  If your device claimed to be a 
mass storage device, or a keyboard, or a set of speakers, or a web 
camera, then one of the standard drivers would have claimed it.  But in 
your case, the QuickUSB is defined as a "vendor-defined" device.  That 
means no driver will claim it.  Therefore, THERE IS NOTHING FOR 
usb_get_driver_np TO DO.  You should GET RID OF IT.


> I'm looking at this function on linux.c:
>
> int usb_get_driver_np(usb_dev_handle *dev, int interface, char *name,
>     unsigned int namelen)

You should not look at this function.  Instead, you should eliminate 
your call to it.  You don't need this.  The error message it returns is 
perfectly normal and will not affect your application.  I don't know how 
many times I can say this.


> I don't know what to do next... I may try the kernel driver for now.

What kernel driver?

-- 
Tim Roberts, ti...@pr...
Providenza & Boekelheide, Inc.