currently, when a zlp flag is set and an urb/usb_request buffer is filled without a short packet, transfer() leaves its status at -EINPROGRESS and does not rescan for short packet. In a scenario where ep.maxpacket bytes are copied, URB_ZERO_PACKET is set, urb buffer is filled and usb_request buffer is not, transfer() returns with an urb with -EINPROGRESS status, which dummy_hcd treats as incomplete transfer. Check for zlp and rescan appropriately. Signed-off-by: Igor Kotrasinski <i.kotrasinsk@xxxxxxxxxxx> --- drivers/usb/gadget/udc/dummy_hcd.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c index 181112c..59be03e 100644 --- a/drivers/usb/gadget/udc/dummy_hcd.c +++ b/drivers/usb/gadget/udc/dummy_hcd.c @@ -1364,15 +1364,23 @@ top: req->req.status = 0; } - /* many requests terminate without a short packet */ + /* many requests terminate without a short packet. + * send a zlp if demanded by flags. + */ } else { - if (req->req.length == req->req.actual - && !req->req.zero) - req->req.status = 0; - if (urb->transfer_buffer_length == urb->actual_length - && !(urb->transfer_flags - & URB_ZERO_PACKET)) - *status = 0; + if (req->req.length == req->req.actual) { + if (req->req.zero && to_host) + rescan = 1; + else + req->req.status = 0; + } + if (urb->transfer_buffer_length == urb->actual_length) { + if (urb->transfer_flags & URB_ZERO_PACKET && + !to_host) + rescan = 1; + else + *status = 0; + } } /* device side completion --> continuable */ -- 1.9.1 -- 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