[PATCH v3 3/3] usb: chipidea: udc: improve error recovery for ISO transfer

Xu Yang
2024-09-26T02:28:14Z

Impove device mode ISO transfer error tolerant by reprime the corresponding
endpoint.

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

Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
Changes in v2:
- modify commit message
- keep "hwreq->req.status = tmptoken & TD_STATUS"
- giveback status 0 to user for isoc error case
Changes in v3:
- add Acked-by tag
---
drivers/usb/chipidea/udc.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 0132bb25c9b5..18c1882cf088 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;
@@ -715,11 +716,15 @@ 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 = 0;
+ } else {
+ 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