[PATCH v2 1/3] usb: dwc3: gadget: Refactor EP0 forced stall/restart into a separate API

[Wesley Cheng <quic_wcheng@xxxxxxxxxxx>]

Several sequences utilize the same routine for forcing the control endpoint
back into the SETUP phase.  This is required, because those operations need
to ensure that EP0 is back in the default state.

Fixes: c96683798e27 ("usb: dwc3: ep0: Don't prepare beyond Setup stage")
Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---
 drivers/usb/dwc3/gadget.c | 44 ++++++++++++++++++---------------------
 1 file changed, 20 insertions(+), 24 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 3c63fa97a680..320e30476c88 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -139,6 +139,24 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
 	return -ETIMEDOUT;
 }
 
+static void dwc3_ep0_reset_state(struct dwc3 *dwc)
+{
+	unsigned int	dir;
+
+	if (dwc->ep0state != EP0_SETUP_PHASE) {
+		dir = !!dwc->ep0_expect_in;
+		if (dwc->ep0state == EP0_DATA_PHASE)
+			dwc3_ep0_end_control_data(dwc, dwc->eps[dir]);
+		else
+			dwc3_ep0_end_control_data(dwc, dwc->eps[!dir]);
+
+		dwc->eps[0]->trb_enqueue = 0;
+		dwc->eps[1]->trb_enqueue = 0;
+
+		dwc3_ep0_stall_and_restart(dwc);
+	}
+}
+
 /**
  * dwc3_ep_inc_trb - increment a trb index.
  * @index: Pointer to the TRB index to increment.
@@ -3821,16 +3839,7 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
 	dwc->setup_packet_pending = false;
 	usb_gadget_set_state(dwc->gadget, USB_STATE_NOTATTACHED);
 
-	if (dwc->ep0state != EP0_SETUP_PHASE) {
-		unsigned int    dir;
-
-		dir = !!dwc->ep0_expect_in;
-		if (dwc->ep0state == EP0_DATA_PHASE)
-			dwc3_ep0_end_control_data(dwc, dwc->eps[dir]);
-		else
-			dwc3_ep0_end_control_data(dwc, dwc->eps[!dir]);
-		dwc3_ep0_stall_and_restart(dwc);
-	}
+	dwc3_ep0_reset_state(dwc);
 }
 
 static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
@@ -3884,20 +3893,7 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 	 * phase. So ensure that EP0 is in setup phase by issuing a stall
 	 * and restart if EP0 is not in setup phase.
 	 */
-	if (dwc->ep0state != EP0_SETUP_PHASE) {
-		unsigned int	dir;
-
-		dir = !!dwc->ep0_expect_in;
-		if (dwc->ep0state == EP0_DATA_PHASE)
-			dwc3_ep0_end_control_data(dwc, dwc->eps[dir]);
-		else
-			dwc3_ep0_end_control_data(dwc, dwc->eps[!dir]);
-
-		dwc->eps[0]->trb_enqueue = 0;
-		dwc->eps[1]->trb_enqueue = 0;
-
-		dwc3_ep0_stall_and_restart(dwc);
-	}
+	dwc3_ep0_reset_state(dwc);
 
 	/*
 	 * In the Synopsis DesignWare Cores USB3 Databook Rev. 3.30a