[PATCH 1/1] usb: cdns3: gadget: own the lock wrongly at the suspend routine

[Peter Chen <peter.chen@nxp.com>]

When it is device mode with cable connected to host, the call
stack is: cdns3_suspend->cdns3_gadget_suspend->cdns3_disconnect_gadget,
the cdns3_disconnect_gadget owns lock wrongly at this situation,
it causes the system being deadlock after resume due to at
cdns3_device_thread_irq_handler, it tries to get the lock, but will
never get it.

To fix it, we delete the lock operations, and add them at the caller
when necessary.

Cc: stable <stable@vger.kernel.org>
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
 drivers/usb/cdns3/gadget.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 13027ce6bed8..f6c51cc924a8 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -1674,11 +1674,8 @@ static int cdns3_check_ep_interrupt_proceed(struct cdns3_endpoint *priv_ep)
 
 static void cdns3_disconnect_gadget(struct cdns3_device *priv_dev)
 {
-	if (priv_dev->gadget_driver && priv_dev->gadget_driver->disconnect) {
-		spin_unlock(&priv_dev->lock);
+	if (priv_dev->gadget_driver && priv_dev->gadget_driver->disconnect)
 		priv_dev->gadget_driver->disconnect(&priv_dev->gadget);
-		spin_lock(&priv_dev->lock);
-	}
 }
 
 /**
@@ -1713,8 +1710,10 @@ static void cdns3_check_usb_interrupt_proceed(struct cdns3_device *priv_dev,
 
 	/* Disconnection detected */
 	if (usb_ists & (USB_ISTS_DIS2I | USB_ISTS_DISI)) {
+		spin_unlock(&priv_dev->lock);
 		cdns3_disconnect_gadget(priv_dev);
 		priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
+		spin_lock(&priv_dev->lock);
 		usb_gadget_set_state(&priv_dev->gadget, USB_STATE_NOTATTACHED);
 		cdns3_hw_reset_eps_config(priv_dev);
 	}
-- 
2.17.1