[PATCH v2 0/2] usb: cdns3: two fixes for gadget

[PATCH v2 0/2] usb: cdns3: two fixes for gadget

[Peter Chen]

These two issues are found during run "Error Recovery Test"
for the latest USB CV MSC test, the TRB doesn't advance correctly
after dequeue and clear halt. With these two fixes, the test
can be passed.

Peter Chen (2):
  usb: cdns3: gadget: link trb should point to next request
  usb: cdns3: gadget: toggle cycle bit before reset endpoint

 drivers/usb/cdns3/gadget.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

-- 
2.17.1

[PATCH v2 1/2] usb: cdns3: gadget: link trb should point to next request

[Peter Chen]

It has marked the dequeue trb as link trb, but its next segment
pointer is still itself, it causes the transfer can't go on. Fix
it by set its pointer as the trb address for the next request.

Fixes: f616c3bda47e ("usb: cdns3: Fix dequeue implementation")
Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
No changes.

 drivers/usb/cdns3/gadget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 736b0c6e27fe..1d8a2af35bb0 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -2550,7 +2550,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
 	/* Update ring only if removed request is on pending_req_list list */
 	if (req_on_hw_ring) {
 		link_trb->buffer = TRB_BUFFER(priv_ep->trb_pool_dma +
-					      (priv_req->start_trb * TRB_SIZE));
+			((priv_req->end_trb + 1) * TRB_SIZE));
 		link_trb->control = (link_trb->control & TRB_CYCLE) |
 				    TRB_TYPE(TRB_LINK) | TRB_CHAIN;
 
-- 
2.17.1

[PATCH v2 2/2] usb: cdns3: gadget: toggle cycle bit before reset endpoint

[Peter Chen]

If there are TRBs pending during reset endpoint operation, the
DMA will advance after reset operation, but it isn't expected,
since the data is not yet available (For OUT, the data is not
yet available). After the data is ready, there won't be any
interrupt since the EP_TRADDR already points to next TRB entry
and doorbell is not set.

To fix it, it toggles cycle bit before reset operation, and restores
it after reset, it could avoid unexpected DMA advance due to
cycle bit is for software during the endpoint reset operation.

Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
Changes for v2:
- Improve the comments.
- Using MACRO TRB_CYCLE at code

 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..3574dbb09366 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 ^ TRB_CYCLE;
+	}
+
 	writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
 
 	/* 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 ^ TRB_CYCLE;
 		cdns3_rearm_transfer(priv_ep, 1);
+	}
 
 	cdns3_start_all_request(priv_dev, priv_ep);
 	return ret;
-- 
2.17.1

Re: [PATCH v2 0/2] usb: cdns3: two fixes for gadget

[Peter Chen]

On Wed, Feb 19, 2020 at 10:16 PM Peter Chen <peter.chen@nxp.com> wrote:
>
> These two issues are found during run "Error Recovery Test"
> for the latest USB CV MSC test, the TRB doesn't advance correctly
> after dequeue and clear halt. With these two fixes, the test
> can be passed.
>
> Peter Chen (2):
>   usb: cdns3: gadget: link trb should point to next request
>   usb: cdns3: gadget: toggle cycle bit before reset endpoint
>
>  drivers/usb/cdns3/gadget.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
>

A gentle ping...

Peter

Re: [PATCH v2 0/2] usb: cdns3: two fixes for gadget

[Greg Kroah-Hartman]

On Thu, Feb 27, 2020 at 09:26:49AM +0800, Peter Chen wrote:
> On Wed, Feb 19, 2020 at 10:16 PM Peter Chen <peter.chen@nxp.com> wrote:
> >
> > These two issues are found during run "Error Recovery Test"
> > for the latest USB CV MSC test, the TRB doesn't advance correctly
> > after dequeue and clear halt. With these two fixes, the test
> > can be passed.
> >
> > Peter Chen (2):
> >   usb: cdns3: gadget: link trb should point to next request
> >   usb: cdns3: gadget: toggle cycle bit before reset endpoint
> >
> >  drivers/usb/cdns3/gadget.c | 19 +++++++++++++++----
> >  1 file changed, 15 insertions(+), 4 deletions(-)
> >
> 
> A gentle ping...

I can take these now, thanks.

greg k-h