[PATCH 4.9 27/41] usb: gadget: udc: renesas_usb3: Fix usb_gadget_giveback_request() calling

Greg Kroah-Hartman
2017-08-15T01:19:35Z

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

commit aca5b9ebd096039657417c321a9252c696b359c2 upstream.

According to the gadget.h, a "complete" function will always be called
with interrupts disabled. However, sometimes usb3_request_done() function
is called with interrupts enabled. So, this function should be held
by spin_lock_irqsave() to disable interruption. Also, this driver has
to call spin_unlock() to avoid spinlock recursion by this driver before
calling usb_gadget_giveback_request().

Reported-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Tested-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
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 | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -685,21 +685,32 @@ static struct renesas_usb3_request *usb3
return usb3_req;
}

-static void usb3_request_done(struct renesas_usb3_ep *usb3_ep,
- struct renesas_usb3_request *usb3_req, int status)
+static void __usb3_request_done(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req,
+ int status)
{
struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
- unsigned long flags;

dev_dbg(usb3_to_dev(usb3), "giveback: ep%2d, %u, %u, %d\n",
usb3_ep->num, usb3_req->req.length, usb3_req->req.actual,
status);
usb3_req->req.status = status;
- spin_lock_irqsave(&usb3->lock, flags);
usb3_ep->started = false;
list_del_init(&usb3_req->queue);
- spin_unlock_irqrestore(&usb3->lock, flags);
+ spin_unlock(&usb3->lock);
usb_gadget_giveback_request(&usb3_ep->ep, &usb3_req->req);
+ spin_lock(&usb3->lock);
+}
+
+static void usb3_request_done(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req, int status)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ unsigned long flags;
+
+ spin_lock_irqsave(&usb3->lock, flags);
+ __usb3_request_done(usb3_ep, usb3_req, status);
+ spin_unlock_irqrestore(&usb3->lock, flags);
}

static void usb3_irq_epc_pipe0_status_end(struct renesas_usb3 *usb3)