usb: dwc3: gadget: synchronize_irq dwc irq in suspend

[ Upstream commit 01c10880d24291a96a4ab0da773e3c5ce4d12da8 ]

We see dwc3 endpoint stopped by unwanted irq during
suspend resume test, which is caused dwc3 ep can't be started
with error "No Resource".

Here, add synchronize_irq before suspend to sync the
pending IRQ handlers complete.
Signed-off-by: NBo He <bo.he@intel.com>
Signed-off-by: NYu Wang <yu.y.wang@intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/usb/dwc3/gadget.c

@@ -3274,6 +3274,8 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)
 	dwc3_disconnect_gadget(dwc);
 	__dwc3_gadget_stop(dwc);
 
+	synchronize_irq(dwc->irq_gadget);
+
 	return 0;
 }