On Wed, Jan 09, 2019 at 02:06:31PM -0500, Alan Stern wrote: > On Wed, 9 Jan 2019, Paul Elder wrote: > > > A usb gadget function driver may or may not want to delay the status > > stage of a control OUT request. An instance where it might want to is to > > asynchronously validate the data of a class-specific request. > > > > A function driver that wants an explicit status stage should set the > > newly added explicit_status flag of the usb_request corresponding to the > > data stage. Later on, the function driver can explicitly complete the > > status stage by enqueueing a usb_request for ACK, or calling > > usb_ep_set_halt() for STALL. > > > > To support both explicit and implicit status stages, a UDC driver must > > call the newly added usb_gadget_control_complete function right before > > calling usb_gadget_giveback_request. To support the explicit status > > stage, it might then check what stage the usb_request was queued in, and > > for control IN ACK the host's zero-length data packet, or for control > > OUT send a zero-length DATA1 ACK packet. > > > > Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx> > > v4 Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > v1 Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > This looks good and has passed my tests so far. Good! Thank you :) > Can you check your uvc > changes using dummy_hcd with the patch below? I'm not sure what to make of the test results. I get the same results with or without the patch. Which I guess makes sense... in dummy_queue, this is getting hit when the uvc function driver tries to complete the delayed status: req = usb_request_to_dummy_request(_req); if (!_req || !list_empty(&req->queue) || !_req->complete) return -EINVAL; So the delayed/explicit status stage is never completed, afaict. Paul
