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

Greg Kroah-Hartman
2017-06-19T15:29:24Z

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

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@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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));