On Tue, 7 Jul 2015, Rui Miguel Silva wrote:
> When the request actual state is equal to lenght, besides setting the
"state"? Do you mean "status"?
"lenght" is a typo.
> request status to done, the status variable also need to be updated.
> If not, the status will be EINPROGRESS and the transfer will never be
> set as completed.
The status variable points to the URB, not to the request.
> Signed-off-by: Rui Miguel Silva <rui.silva@xxxxxxxxxx>
> ---
> drivers/usb/gadget/udc/dummy_hcd.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
> index 181112c..f5400b8 100644
> --- a/drivers/usb/gadget/udc/dummy_hcd.c
> +++ b/drivers/usb/gadget/udc/dummy_hcd.c
> @@ -1367,8 +1367,10 @@ top:
> /* many requests terminate without a short packet */
> } else {
> if (req->req.length == req->req.actual
> - && !req->req.zero)
> + && !req->req.zero) {
> req->req.status = 0;
> + *status = 0;
> + }
> if (urb->transfer_buffer_length == urb->actual_length
> && !(urb->transfer_flags
> & URB_ZERO_PACKET))
This patch is wrong. *status should indeed remain -EINPROGRESS and the
transfer should remain incomplete.
Here's an example to illustrate what I mean. Let's say the endpoint's
maxpacket value is 512, and suppose the host queues a 1024-byte IN URB.
In response, suppose the gadget queues two 512-byte requests, each with
req->req.zero clear. Consider what happens when the first request is
processed.
len, req->req.length and req->req.actual are all equal to 512, and
is_short is false. req therefore completes with req->req.status set to
0. But the URB is still in progress! It still has 512 bytes left to
transfer, and it won't complete until the second request finishes.
Therefore *status (which is the URB's status) should remain set to
-EINPROGRESS.
Alan Stern
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