>
>If there are TRBs pending during clear stall and reset endpoint, the
>DMA will advance after reset operation, but it doesn't be expected,
>since the data has still not be ready (For OUT, the data has still
>not received). After the data is ready, there isn't any interrupt
>since the EP_TRADDR has already points to next TRB entry.
>
>To fix it, it toggles cyclt bit before reset operation, and restore
>it after reset, it could keep DMA stopping.
>
>Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
>Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
>---
> drivers/usb/cdns3/gadget.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>index 1d8a2af35bb0..7b6bb96b91d1 100644
>--- a/drivers/usb/cdns3/gadget.c
>+++ b/drivers/usb/cdns3/gadget.c
>@@ -2595,11 +2595,21 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
> {
> struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
> struct usb_request *request;
>+ struct cdns3_request *priv_req;
>+ struct cdns3_trb *trb = NULL;
> int ret;
> int val;
>
> trace_cdns3_halt(priv_ep, 0, 0);
>
>+ request = cdns3_next_request(&priv_ep->pending_req_list);
>+ if (request) {
>+ priv_req = to_cdns3_request(request);
>+ trb = priv_req->trb;
>+ if (trb)
>+ trb->control = trb->control ^ 1;
>+ }
>+
What about doing simple read/write on ep_traddr register:
u32 ep_traddr;
ep_traddr = readl(&priv_dev->regs->ep_traddr);
> writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
writel(&priv_dev->regs->ep_traddr, ep_traddr);
It should work in the same way but is simpler.
And maybe we could add some comment because this code look little strange. Something like:
When endpoint is armed during endpoint reset the controller can advance TRADDR to next TD,
so driver need to restore the previous value.
>
> /* wait for EPRST cleared */
>@@ -2610,10 +2620,11 @@ int __cdns3_gadget_ep_clear_halt(struct cdns3_endpoint *priv_ep)
>
> priv_ep->flags &= ~(EP_STALLED | EP_STALL_PENDING);
>
>- request = cdns3_next_request(&priv_ep->pending_req_list);
>-
>- if (request)
>+ if (request) {
>+ if (trb)
>+ trb->control = trb->control ^ 1;
> cdns3_rearm_transfer(priv_ep, 1);
>+ }
>
> cdns3_start_all_request(priv_dev, priv_ep);
> return ret;
>--
>2.17.1
