usb: dwc3: gadget: Restart DWC3 gadget when enabling pullup

usb_gadget_deactivate/usb_gadget_activate does not execute the UDC start
operation, which may leave EP0 disabled and event IRQs disabled when
re-activating the function. Move the enabling/disabling of USB EP0 and
device event IRQs to be performed in the pullup routine.

Fixes: ae7e8610 ("usb: dwc3: Stop active transfers before halting the controller")
Tested-by: Michael Tretter <m.tretter@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Reported-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1609282837-21666-1-git-send-email-wcheng@codeaurora.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/gadget.c

@@ -2083,6 +2083,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
 
 static void dwc3_gadget_disable_irq(struct dwc3 *dwc);
 static void __dwc3_gadget_stop(struct dwc3 *dwc);
+static int __dwc3_gadget_start(struct dwc3 *dwc);
 
 static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 {
@@ -2145,6 +2146,8 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 			dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) %
 						dwc->ev_buf->length;
 		}
+	} else {
+		__dwc3_gadget_start(dwc);
 	}
 
 	ret = dwc3_gadget_run_stop(dwc, is_on, false);
@@ -2319,10 +2322,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 	}
 
 	dwc->gadget_driver	= driver;
-
-	if (pm_runtime_active(dwc->dev))
-		__dwc3_gadget_start(dwc);
-
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	return 0;
@@ -2348,13 +2347,6 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
 	unsigned long		flags;
 
 	spin_lock_irqsave(&dwc->lock, flags);
-
-	if (pm_runtime_suspended(dwc->dev))
-		goto out;
-
-	__dwc3_gadget_stop(dwc);
-
-out:
 	dwc->gadget_driver	= NULL;
 	spin_unlock_irqrestore(&dwc->lock, flags);