On Thu, Sep 12, 2024 at 11:35:51AM +0800, Xu Yang wrote:
usb: chipidea: udc: improve error recovery for ISO transfer
> 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.
Look like this information is not related with this patch.
>
> 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.
Impove device mode ISO transfer error tolerant by reprime the corresponding
endpont.
>
> 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.
The recovery steps when error occurs:
- Delete the error dTD from dQH and giveback request to user.
- Do reprime if dQH is not empty.
- Do prime when new dTD is queued if dQH is empty
>
> 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;
> 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
>
