Maksim Yevmenkin writes: > The problem is that as soon as i open isochronous pipe and > start incoming isochronous transfer, the isochronous callback > gets called over and over again. Both isoc. pipe and isoc. > transfer have USBD_NO_SHORT_XFER flag set. I also set > configuration #5 for interface 1. The funny part that device > says that it got zero bytes from the pipe. It does not affect > (or so it seems) the other transfers and everything still works. > I also tried ugen driver with the same results. What is up with > that?
My experience with isochronous pipes is the same. I'm working with a couple of webcams and the isoc callback is invoked repeatedly, but always with a size of 0. This occurs in both -stable and -current, tested on two different UHCI chipsets. I also played around with ugen (stock ugen and a userland driver, as well as a "custom ugen") but the results were the same. While I have no other USB devices to try out under FreeBSD, my guess is that the problems are mainly with isoc transfers; there are plenty of supported devices using bulk and interrupt transfers but there is only one case I'm aware of that makes use of isoc transfers. Reportedly a different webcam works under 4.6-RC using ugen and a userland program (/usr/ports/graphics/vid). I'm also a USB newbie so I cannot answer your other questions. Carlos -- Carlos A. Ugarte [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
