On Tue, 11 Nov 2003, Henry Culver wrote: > I am in the process of writing a device driver for a device which is a > combination vacuum flourescent display and ir receiver. The driver is > functional, but has some problems. > > The device has a single configuration, and single interface with 2 endpoints. > The endpoints are transfer type "interrupt". > > My open routine allocates 2 urb's (one for each endpoint, in and out) and > fills them with usb_fill_int_urb. I have an "in" callback routine and an > "out" callback routine. > > I can read ir byte codes from the device and write characters to the display > including control codes which position subsequent character writes, clear > the display and set brightness. > > My problem is that I cannot seem to reuse the out urb. When my write_callback > routine is called, the urb->status is 0, but another write to the device > blocks and the urb->status is thereafter -EINPROGRESS. If in my callback > routine I usb_unlink_urb, usb_free_urb and then usb_alloc_urb(0) and > re-initialize the structure, everything behaves correctly.
I don't understand. What do you mean "another write to the device blocks"? If the write blocked, how would you know what urb->status was afterwards? -- your machine would be locked up. After submission, usb->status is _supposed_ to be -EINPROGRESS; it stays that value more or less until it has completed. > After each successful write, I have to release and then re-allocate the > out urb. Shouldn't I be able to reuse it? If so, does anyone have any > helpful hints as to what might be going on here? You certainly should be able to reuse it. What version of Linux and which host controller driver are you using? If you aren't using 2.6, try it out and see if it works any better. Alan Stern ------------------------------------------------------- This SF.Net email sponsored by: ApacheCon 2003, 16-19 November in Las Vegas. Learn firsthand the latest developments in Apache, PHP, Perl, XML, Java, MySQL, WebDAV, and more! http://www.apachecon.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
