On Fri, Sep 13, 2024 at 09:49:40AM +0800, Peter Chen wrote:
> On 24-09-12 11:35:51, Xu Yang wrote:
> > When a endpoint met errors, the usb controller will firstly assert
> > related error bit in status filed of dTD, then ENDPTCOMPLETE will be
> > asserted. Finally, USBSTS.UEI will be set.
> >
> > Due to isoc transfers are error-tolerant transfers, we can make isoc
> > endpoint a bit error tolerant on device mode too. In case of error,
> > it's possilbe to resume the endpoint by reprime the corresponding
> > endpoint.
> >
> > When error occurs, this will allow error dTD be deleted from dQH and
> > giveback request to user. Then, a reprime/prime operation is executed
> > depends on whether dQH is empty or not. If dQH is not empty, reprime
> > will be done during dequeue process. If dQH is empty, prime will be
> > done when new dTD is linked. In this way, isoc transfer can be recovered
> > from a small number of errors.
> >
> > Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
> > ---
> > drivers/usb/chipidea/udc.c | 12 +++++++-----
> > 1 file changed, 7 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> > index 0ab57b87b07b..b1a1be6439b6 100644
> > --- a/drivers/usb/chipidea/udc.c
> > +++ b/drivers/usb/chipidea/udc.c
> > @@ -683,6 +683,7 @@ static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
> > unsigned remaining_length;
> > unsigned actual = hwreq->req.length;
> > struct ci_hdrc *ci = hwep->ci;
> > + bool is_isoc = hwep->type == USB_ENDPOINT_XFER_ISOC;
> >
> > if (hwreq->req.status != -EALREADY)
> > return -EINVAL;
> > @@ -696,7 +697,7 @@ static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
> > int n = hw_ep_bit(hwep->num, hwep->dir);
> >
> > if (ci->rev == CI_REVISION_24 ||
> > - ci->rev == CI_REVISION_22)
> > + ci->rev == CI_REVISION_22 || is_isoc)
> > if (!hw_read(ci, OP_ENDPTSTAT, BIT(n)))
> > reprime_dtd(ci, hwep, node);
> > hwreq->req.status = -EALREADY;
> > @@ -707,7 +708,6 @@ static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
> > remaining_length >>= __ffs(TD_TOTAL_BYTES);
> > actual -= remaining_length;
> >
> > - hwreq->req.status = tmptoken & TD_STATUS;
>
> Non-ISO dTD may need error status? You may refine code by ISO and
> non-ISOC.
Oh, I have checked this line again, I indeed wrongly remove it.
I have no idea how to refine the code since they will go through
almost same path, otherwise, the code may be a bit duplicated.
Thanks,
Xu Yang
>
> Peter
>
> > if ((TD_STATUS_HALTED & hwreq->req.status)) {
> > hwreq->req.status = -EPIPE;
> > break;
> > @@ -715,11 +715,13 @@ static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
> > hwreq->req.status = -EPROTO;
> > break;
> > } else if ((TD_STATUS_TR_ERR & hwreq->req.status)) {
> > - hwreq->req.status = -EILSEQ;
> > - break;
> > + if (!is_isoc) {
> > + hwreq->req.status = -EILSEQ;
> > + break;
> > + }
> > }
> >
> > - if (remaining_length) {
> > + if (remaining_length && !is_isoc) {
> > if (hwep->dir == TX) {
> > hwreq->req.status = -EPROTO;
> > break;
> > --
> > 2.34.1
> >
