[PATCH v2] usb: dwc: ep0: Update request status in dwc3_ep0_stall_restart

[Uttkarsh Aggarwal]

Current implementation blocks the running operations when Plug-out and
Plug-In is performed continuously, process gets stuck in
dwc3_thread_interrupt().

Code Flow:

	CPU1

	->Gadget_start
	->dwc3_interrupt
	->dwc3_thread_interrupt
	->dwc3_process_event_buf
	->dwc3_process_event_entry
	->dwc3_endpoint_interrupt
	->dwc3_ep0_interrupt
	->dwc3_ep0_inspect_setup
	->dwc3_ep0_stall_and_restart

By this time if pending_list is not empty, it will get the next request
on the given list and calls dwc3_gadget_giveback which will unmap request
and call its complete() callback to notify upper layers that it has
completed. Currently dwc3_gadget_giveback status is set to -ECONNRESET,
whereas it should be -ESHUTDOWN based on condition if not dwc->connected
is true.

Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: d742220b3577 ("usb: dwc3: ep0: giveback requests on stall_and_restart")
Signed-off-by: Uttkarsh Aggarwal <quic_uaggarwa@xxxxxxxxxxx>
---

Changes in v2:
Added dwc->connected check to set status either -ESHUTDOWN and -ECONNRESET 
in dwc3_gadget_giveback.

Link to v1:
https://lore.kernel.org/all/20231122091127.3636-1-quic_uaggarwa@xxxxxxxxxxx/T/#m28b011642024788c507d8b7eee4f7c5b0709d236

 drivers/usb/dwc3/ep0.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index b94243237293..816b8eea73d6 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -238,7 +238,10 @@ void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
 		struct dwc3_request	*req;
 
 		req = next_request(&dep->pending_list);
-		dwc3_gadget_giveback(dep, req, -ECONNRESET);
+		if (!dwc->connected)
+			dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
+		else
+			dwc3_gadget_giveback(dep, req, -ECONNRESET);
 	}
 
 	dwc->eps[0]->trb_enqueue = 0;
-- 
2.17.1