On Mon, 17 Oct 2011, Markus Rechberger wrote: > HW engineers are checking the device again also with bus analyzer. I > also end up that there > must be some issue with the device as the other devices just work fine > with bulk and small buffers. > I'll see what will come up for that one. For the other device I wonder > why the no interrupt flag doesn't > seem to help, does a short transfer automatically trigger an interrupt > when the device is set to use small buffers? If the host controller receives a packet that is shorter than the expected size then an interrupt will indeed be generated, even if the URB_NO_INTERRUPT flag is set. The device settings don't matter; all that matters is the size of the packet received by the host. For each packet, the expected size is the smaller of: the amount still left in the transfer, and the wMaxPacketSize value. Assuming wMaxPacketSize is 512 (which it should be, for a high-speed bulk endpoint), if the transfer length is 12288 or 11776 then the expected packet size is always 512. 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
