On Thu, 12 Jul 2012, Dipen Patel wrote: > > Hi Ron/Greg, > > I am facing similar issue with serial gadget configured on i.MX6Q > Sabrelite board. > > In my case Host sends packets starting with 10 bytes to 2MB bytes in > increments of 1 byte. And device simply loopback the same packet with > status byte. > > However everything works fine until Tx (reply) packet size from device > is 16895 bytes. For Tx packet size >= 16896 Host is unable to receive > last few bytes. For Tx size of 16896 I can see on host usbmon trace that > all bytes are received but still waiting for transaction to complete. > And for Tx size more than 16896 it is still waiting for last few bytes. > And eventually Host application will time out. > > In my device side transmit routine I have tried sending whole packet at > once. And also dividing packet into smaller chunks (4096, 8192, 16384) > but same behavior. > > I can receive data upto 2MB so receive looks fine. It's noteworthy that 16896 is a multiple of 512, which is probably your wMaxPacketSize. This suggests that the device needs to send a zero-length packet to tell the host there's no more data available. Alan Stern -- 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
