[PATCH] usb: gadget: composite: unlock spinlock before usb_gadget_disconnect()

From: Robert Baldyga
Date: Fri Jun 13 2014 - 07:28:55 EST


usb_gadget_disconnect() shouldn't be called under spinlock to avoid
spinlock recursion. Function usb_gadget_disconnect() calls pullup(),
which is callback from UDC driver, usually calling composite_disconnect().
This function wants to lock spinlock used in usb_function_deactivate()
causing spinlock recursion.

Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index d41103e..77cae4b 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -260,8 +260,11 @@ int usb_function_deactivate(struct usb_function *function)

spin_lock_irqsave(&cdev->lock, flags);

- if (cdev->deactivations == 0)
+ if (cdev->deactivations == 0) {
+ spin_unlock_irqrestore(&cdev->lock, flags);
status = usb_gadget_disconnect(cdev->gadget);
+ spin_lock_irqsave(&cdev->lock, flags);
+ }
if (status == 0)
cdev->deactivations++;

--
1.9.1

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