[PATCH 4.9 31/60] usb: gadget: udc: renesas_usb3: fix deadlock by spinlock

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>

commit 067d6fdc558d2c43f0bfdc7af99630dd5eb08dc5 upstream.

This patch fixes an issue that this driver is possible to cause
deadlock by double-spinclocked in renesas_usb3_stop_controller().
So, this patch removes spinlock API calling in renesas_usb3_stop().
(In other words, the previous code had a redundant lock.)

Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/gadget/udc/renesas_usb3.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -1718,14 +1718,11 @@ static int renesas_usb3_start(struct usb
 static int renesas_usb3_stop(struct usb_gadget *gadget)
 {
 	struct renesas_usb3 *usb3 = gadget_to_renesas_usb3(gadget);
-	unsigned long flags;
 
-	spin_lock_irqsave(&usb3->lock, flags);
 	usb3->softconnect = false;
 	usb3->gadget.speed = USB_SPEED_UNKNOWN;
 	usb3->driver = NULL;
 	renesas_usb3_stop_controller(usb3);
-	spin_unlock_irqrestore(&usb3->lock, flags);
 
 	pm_runtime_put(usb3_to_dev(usb3));
 	pm_runtime_disable(usb3_to_dev(usb3));