On Thu, Oct 03, 2013 at 06:00:50PM -0000, hemantk@xxxxxxxxxxxxxx wrote: > We have devices which require to send zero length packet in data stage to > host in certain cases. We were not seeing any issue when we were using > ehci based controller. When we switched to XHCI here is what we are > observing:- > > For IN DATA dir control xfer XHCI sets ISP so xhci updates actual_length > for short packet in data stage using event->transfer_len. > > But for data packets not short xhci directly uses > urb->transfer_buffer_length as actual_length.This is done assuming data > stage will never have zero length (short packet) data packet. Once Device > sends zero length packet in data stage > ISP triggers and actual_length is updated with value 0. Then later in > status stage (since urb->actual_length is zero) driver incorrectly sets > actual_length with urb->transfer_buffer_length. > > > I would like to get insight from linux-usb grp to fix this issue. What kernel version are you seeing these problems? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
