On Mon, Jan 21, 2002 at 05:00:31PM -0700, Gordon McNutt wrote: > I've got a situation where the callback for an urb fires which wakes up > a user process which checks the urb status and finds that it's zero.
How does a user process check an urb status? Are you spinning in the callback waiting for a user process to wake up? Is this a kernel driver, or are you using usbfs/usbdevfs? > But the next time the user process tries to submit the urb > usb_submit_urb() returns -ENODEV becaus urb->dev is NULL. You need to set urb->dev before calling usb_submit_urb() every time. > How is a driver supposed to determine that the USB subsystem is actually > done with an URB? I can't believe that it has to do something like poll > urb->dev... Ah, welcome to the mess :) The callback function should set a flag saying that this urb is now finished. See the long flame^Wdiscussion on this list last week for more details about this than you probably wanted to know. Hope this helps, greg k-h _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
