On Wed, 8 Sep 2004 [EMAIL PROTECTED] wrote: > Configuration: > Distribution:Linux Fedora Core 2 > Kernel:2.6.7 > Problem occured also with the RedHat 7.3 distribution (kernel 2.4.18) > HCD:uhci_hcd > > Hi, > I'm writing an USB driver for a specific device. > If I terminate an IO (a read on a BULK or an interrupt pipe) by calling > usb_unlink_urb() > then I submit another URB, I miss some data. With an USB analyser, I can > see a packet that is missed.
(I assume the packet was sent in response to the first URB, not the second.) The data will be available in the transfer_buffer for the URB that you unlinked. The amount of data in the buffer is urb->actual_length. That's true even though urb->status is -ECONNRESET or -ENOENT. > The driver IO completion call-back will never be called until the device > send other data. Do you mean the completion handler for the second URB? The handler for the first URB will be called shortly after you unlink it. A more interesting question is: Why do you have to unlink the URB to terminate the I/O transfer? Why doesn't the transfer terminate by itself when the device has sent all the data it has available? Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
