On Wed, 20 Aug 2014, Felipe Balbi wrote:
> On Tue, Jul 15, 2014 at 10:07:40PM +0800, Li Jun wrote:
> > This patch try to dequeue the cdev->req to guarantee the request is not queued
> > before free it.
> >
> > Signed-off-by: Li Jun <b47624@xxxxxxxxxxxxx>
> > ---
> > drivers/usb/gadget/composite.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> > index f801519..6935a82 100644
> > --- a/drivers/usb/gadget/composite.c
> > +++ b/drivers/usb/gadget/composite.c
> > @@ -1956,6 +1956,7 @@ void composite_dev_cleanup(struct usb_composite_dev *cdev)
> > }
> > if (cdev->req) {
> > kfree(cdev->req->buf);
> > + usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
>
> it's best to dequeue the request before freeing its buffer.
In fact, it's best to wait for the request's completion routine to be
called before freeing the buffer. The hardware can access the buffer's
memory at any time before the completion routine runs.
Alan Stern
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