Re: [PATCH] usb: gadget: uvc_video: unlock before submitting a request to ep

[Thinh Nguyen]

Hi,

On Wed, Jan 10, 2024, Pandey, Radhey Shyam wrote:
> 
> Thanks, Thinh. I came across this thread and wanted to check if you 
> have some fix ready?

Would you mind test this change to see if it fixes the issue:

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 8d1881adcd80..f40c7b9105cc 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1808,6 +1808,7 @@ static int dwc3_prepare_trbs(struct dwc3_ep *dep)
 	return ret;
 }
 
+static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *req);
 static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep);
 static void dwc3_gadget_restore_requests(struct dwc3_ep *dep);
 
@@ -1874,9 +1875,27 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
 		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
 			dwc3_gadget_move_cancelled_request(req, DWC3_REQUEST_STATUS_DEQUEUED);
 
-		/* If ep isn't started, then there's no end transfer pending */
-		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
-			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+		if ((dep->flags & DWC3_EP_DELAY_START) ||
+		    (dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE) ||
+		    (dep->flags & DWC3_EP_TRANSFER_STARTED)) {
+			/* If ep isn't started, then there's no end transfer pending */
+			if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
+				dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+		} else {
+			/*
+			 * To be in this condition means usb_ep_queue() isn't
+			 * completed yet. Since the controller hasn't owned the
+			 * requests yet, don't give back the requests on failed
+			 * usb_ep_queue. Simply remove them from the endpoint's
+			 * list.
+			 */
+			while (!list_empty(&dep->cancelled_list)) {
+				req = next_request(&dep->cancelled_list);
+				dwc3_gadget_ep_skip_trbs(dep, req);
+				dwc3_gadget_del_and_unmap_request(dep, req, -EINPROGRESS);
+				req->status = DWC3_REQUEST_STATUS_COMPLETED;
+			}
+		}
 
 		return ret;
 	}

BTW, what was the error code returned from usb_ep_queue()? Is it
-ETIMEDOUT?

Thanks,
Thinh