On Fri, 31 Mar 2006, StephenChen wrote:
> I try to submit some urbs to the usb printers , like GET_DESCRIPTOR
> but I found one of the printer(HP Laser Jet 3020) wll result in
> "Device or Resource Busy" when I try CLAIM_INTERFACE or BULK_TRANSFER
> How do i solve this problem to continue to use the usb printer
To my knowledge, interface claiming cannot be done by submitting an URB.
How are you doing this, actually?
If usb_claim_interface() returns -EBUSY, this means there's already
another (possibly kernel) driver bound to that interface. On Linux you
can try usb_get_driver_np() to figure out which driver it is, and
usb_detach_kernel_driver_np() to detach it from this interface (and
retry claiming). You could also try to disable/remove the offending
BULK transfers cannot work if the interface the BULK endpoint belongs to
is claimed by someone else.
Hope this helps.