On Fri, 11 Sep 2015, Igor Kotrasinski wrote:
> 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>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
I can't believe we missed this for so long... This should be marked
for -stable.
While you're at it, you might like to clean up a few other things. For
example, just before the code changed in this patch we have:
...
} else if (to_host) {
...
} else if (!to_host) {
...
Obviously the "if (!to_host)" test is unnecessary.
Also, a little above that we have:
is_short = (len % ep->ep.maxpacket) != 0;
But at this point we know that len != 0, and we also know that if len
>= ep->ep.maxpacket then in fact len is a multiple of ep->ep.maxpacket.
Hence the computation can be simplified to:
is_short = (len < ep->ep.maxpacket);
Alan Stern
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