On Thu, Apr 21, 2022 at 07:23:03PM -0700, Thinh Nguyen wrote:
> If the controller hasn't DMA'ed the Setup data from its fifo, it won't
> process the End Transfer command. Polling for the command completion may
> block the driver from servicing the Setup phase and cause a timeout.
> Previously we only check and delay issuing End Transfer in the case of
> endpoint dequeue. Let's do that for all End Transfer scenarios.
>
> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc3/gadget.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 7c4d5f671687..f0fd7c32828b 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2056,16 +2056,6 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
> if (r == req) {
> struct dwc3_request *t;
>
> - /*
> - * If a Setup packet is received but yet to DMA out, the controller will
> - * not process the End Transfer command of any endpoint. Polling of its
> - * DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
> - * timeout. Delay issuing the End Transfer command until the Setup TRB is
> - * prepared.
> - */
> - if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status)
> - dep->flags |= DWC3_EP_DELAY_STOP;
> -
> /* wait until it is processed */
> dwc3_stop_active_transfer(dep, true, true);
>
> @@ -3657,6 +3647,18 @@ void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
> (dep->flags & DWC3_EP_END_TRANSFER_PENDING))
> return;
>
> + /*
> + * If a Setup packet is received but yet to DMA out, the controller will
> + * not process the End Transfer command of any endpoint. Polling of its
> + * DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
> + * timeout. Delay issuing the End Transfer command until the Setup TRB is
> + * prepared.
> + */
> + if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status) {
> + dep->flags |= DWC3_EP_DELAY_STOP;
> + return;
> + }
> +
dwc3_remove_requests() calls dwc3_stop_active_transfer() but does not check
any flags before retiring all the requests. should we add some assert/WARN_ON
to make sure that we are not retiring the requests before stopping the active
transfers?
Thanks,
Pavan
