[PATCH v2] usb: dwc3: gadget: Don't delay End Transfer on delayed_status

[Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>]

The gadget driver may wait on the request completion when it sets the
USB_GADGET_DELAYED_STATUS. Make sure that the End Transfer command can
go through if the dwc->delayed_status is set so that the request can
complete. When the delayed_status is set, the Setup packet is already
processed, and the next phase should be either Data or Status. It's
unlikely that the host would cancel the control transfer and send a new
Setup packet during End Transfer command. But if that's the case, we can
try again when ep0state returns to EP0_SETUP_PHASE.

Fixes: e1ee843488d5 ("usb: dwc3: gadget: Force sending delayed status during soft disconnect")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
---
 Changes in v2:
 - Fix build issue due to cherry-picking...

 drivers/usb/dwc3/gadget.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 079cd333632e..dd8ecbe61bec 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1698,6 +1698,16 @@ static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool int
 	cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
 	memset(&params, 0, sizeof(params));
 	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
+	/*
+	 * If the End Transfer command was timed out while the device is
+	 * not in SETUP phase, it's possible that an incoming Setup packet
+	 * may prevent the command's completion. Let's retry when the
+	 * ep0state returns to EP0_SETUP_PHASE.
+	 */
+	if (ret == -ETIMEDOUT && dep->dwc->ep0state != EP0_SETUP_PHASE) {
+		dep->flags |= DWC3_EP_DELAY_STOP;
+		return 0;
+	}
 	WARN_ON_ONCE(ret);
 	dep->resource_index = 0;
 
@@ -3719,7 +3729,7 @@ void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
 	 * timeout. Delay issuing the End Transfer command until the Setup TRB is
 	 * prepared.
 	 */
-	if (dwc->ep0state != EP0_SETUP_PHASE) {
+	if (dwc->ep0state != EP0_SETUP_PHASE && !dwc->delayed_status) {
 		dep->flags |= DWC3_EP_DELAY_STOP;
 		return;
 	}

base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780
-- 
2.28.0