Re: [PATCH] usb: cdns3: Fix dequeue implementation.

From: Peter Chen
Date: Tue Oct 08 2019 - 22:32:03 EST


On 19-10-08 08:01:19, Pawel Laszczak wrote:
> >>
> >> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
> >> index 2ca280f4c054..9050b380ab83 100644
> >> --- a/drivers/usb/cdns3/gadget.c
> >> +++ b/drivers/usb/cdns3/gadget.c
> >> @@ -1145,6 +1145,14 @@ static void cdns3_transfer_completed(struct cdns3_device *priv_dev,
> >> request = cdns3_next_request(&priv_ep->pending_req_list);
> >> priv_req = to_cdns3_request(request);
> >>
> >> + trb = priv_ep->trb_pool + priv_ep->dequeue;
> >> +
> >> + /* Request was dequeued and TRB was changed to TRB_LINK. */
> >> + if (TRB_FIELD_TO_TYPE(trb->control) == TRB_LINK) {
> >> + trace_cdns3_complete_trb(priv_ep, trb);
> >> + cdns3_move_deq_to_next_trb(priv_req);
> >> + }
> >
> >If the request was dequeued, it should not be at request list, isn't it?
>
> Yes
> The dequeued request was removed from pending list but TRB associated with it
> was changed to Link TRB so it should be ignored in cdns3_transfer_completed function.
>

I see, you are right. Except for the typo, otherwise:

Reviewed-by: Peter Chen <peter.chen@xxxxxxx>

Peter


> Pawel
>
> >
> >Peter
> >> +
> >> /* Re-select endpoint. It could be changed by other CPU during
> >> * handling usb_gadget_giveback_request.
> >> */
> >> @@ -2067,6 +2075,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
> >> struct usb_request *req, *req_temp;
> >> struct cdns3_request *priv_req;
> >> struct cdns3_trb *link_trb;
> >> + u8 req_on_hw_ring = 0;
> >> unsigned long flags;
> >> int ret = 0;
> >>
> >> @@ -2083,8 +2092,10 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
> >>
> >> list_for_each_entry_safe(req, req_temp, &priv_ep->pending_req_list,
> >> list) {
> >> - if (request == req)
> >> + if (request == req) {
> >> + req_on_hw_ring = 1;
> >> goto found;
> >> + }
> >> }
> >>
> >> list_for_each_entry_safe(req, req_temp, &priv_ep->deferred_req_list,
> >> @@ -2096,27 +2107,21 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
> >> goto not_found;
> >>
> >> found:
> >> -
> >> - if (priv_ep->wa1_trb == priv_req->trb)
> >> - cdns3_wa1_restore_cycle_bit(priv_ep);
> >> -
> >> link_trb = priv_req->trb;
> >> - cdns3_move_deq_to_next_trb(priv_req);
> >> - cdns3_gadget_giveback(priv_ep, priv_req, -ECONNRESET);
> >> -
> >> - /* Update ring */
> >> - request = cdns3_next_request(&priv_ep->deferred_req_list);
> >> - if (request) {
> >> - priv_req = to_cdns3_request(request);
> >>
> >> + /* Update ring only if removed request is on pending_req_list list */
> >> + if (req_on_hw_ring) {
> >> link_trb->buffer = TRB_BUFFER(priv_ep->trb_pool_dma +
> >> (priv_req->start_trb * TRB_SIZE));
> >> link_trb->control = (link_trb->control & TRB_CYCLE) |
> >> - TRB_TYPE(TRB_LINK) | TRB_CHAIN | TRB_TOGGLE;
> >> - } else {
> >> - priv_ep->flags |= EP_UPDATE_EP_TRBADDR;
> >> + TRB_TYPE(TRB_LINK) | TRB_CHAIN;
> >> +
> >> + if (priv_ep->wa1_trb == priv_req->trb)
> >> + cdns3_wa1_restore_cycle_bit(priv_ep);
> >> }
> >>
> >> + cdns3_gadget_giveback(priv_ep, priv_req, -ECONNRESET);
> >> +
> >> not_found:
> >> spin_unlock_irqrestore(&priv_dev->lock, flags);
> >> return ret;
> >
> >--
> >
> >Thanks,
> >Peter Chen

--

Thanks,
Peter Chen