[PATCH 5.4 006/151] usb: dwc3: gadget: Continue to process pending requests

From: Greg Kroah-Hartman
Date: Tue Nov 17 2020 - 08:23:24 EST


From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

[ Upstream commit d9feef974e0d8cb6842533c92476a1b32a41ba31 ]

If there are still pending requests because no TRB was available,
prepare more when started requests are completed.

Introduce dwc3_gadget_ep_should_continue() to check for incomplete and
pending requests to resume updating new TRBs to the controller's TRB
cache.

Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 1d65de84464d5..b6a454211329b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2644,10 +2644,8 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,

req->request.actual = req->request.length - req->remaining;

- if (!dwc3_gadget_ep_request_completed(req)) {
- __dwc3_gadget_kick_transfer(dep);
+ if (!dwc3_gadget_ep_request_completed(req))
goto out;
- }

dwc3_gadget_giveback(dep, req, status);

@@ -2671,6 +2669,24 @@ static void dwc3_gadget_ep_cleanup_completed_requests(struct dwc3_ep *dep,
}
}

+static bool dwc3_gadget_ep_should_continue(struct dwc3_ep *dep)
+{
+ struct dwc3_request *req;
+
+ if (!list_empty(&dep->pending_list))
+ return true;
+
+ /*
+ * We only need to check the first entry of the started list. We can
+ * assume the completed requests are removed from the started list.
+ */
+ req = next_request(&dep->started_list);
+ if (!req)
+ return false;
+
+ return !dwc3_gadget_ep_request_completed(req);
+}
+
static void dwc3_gadget_endpoint_frame_from_event(struct dwc3_ep *dep,
const struct dwc3_event_depevt *event)
{
@@ -2700,6 +2716,8 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,

if (stop)
dwc3_stop_active_transfer(dep, true, true);
+ else if (dwc3_gadget_ep_should_continue(dep))
+ __dwc3_gadget_kick_transfer(dep);

/*
* WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
--
2.27.0