On Fri, 10 Mar 2006, Marc Singer wrote: > > > My interpretation of this sequence is that the host asks for the data > > > with the EINPROGRESS message and the UDC is responding with a fault. > > > > No. The UDC is responding with a packet of length 0 (as you can see from > > the usbmon line) whereas the host requested a packet of length 512. > > That's why it's called a short response. > > OK. Now I get it. I was looking for the code that generate the > EREMOTEIO error so that I could inspect the UDC response.
You mean the code that sets urb->status to -EREMOTEIO? That's part of the HCD. > > > There is an EREMOTEIO in the zero driver that comes from a buffer > > > overrun. printk's show that that it isn't the source. > > > > > > I can tell that the UDC driver is sending at least one packet. On the > > > first interrupt, I load a second packet into the FIFO and tell the UDC > > > to go, but it never appears to transmit this packet. Moreover the > > > host seems to have received an error so it is likely that the UDC is > > > just idle pending a request. > > > > No, it is actually sending a response. If the UDC were sending NAK (data > > not ready), the test would have timed out and given you -ETIMEDOUT, not > > -EREMOTEIO. > > Are these responses generated by the HCD? No, the response packet is generated by your UDC. The HCD then takes the data regarding the packet from the host controller and uses it to fill in urb->status. In this case there wasn't much data to work with, since the packet had length 0. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
