Subject: Re: [patch 3/3] hci_usb.h: fix hard-to-trigger race

From: David Miller <davem-fT/PcQaiUtIeIZ0/[email-masked]>
Date: Fri, 18 Apr 2008 15:41:07 -0700 (PDT)

From: Andrew Morton <akpm-de/[email-masked]>
Date: Fri, 18 Apr 2008 14:21:53 -0700

> On Fri, 18 Apr 2008 23:10:12 +0200
> Marcel Holtmann <[email-masked]> wrote:
> 
> > Hi Andrew,
> > 
> > > From: Pavel Machek <[email-masked]>
> > >
> > > If someone tries to _urb_unlink while _urb_queue_head is running,  
> > > he'll see
> > > _urb->queue == NULL and fail to do any locking.  Prevent that from  
> > > happening
> > > by strategically placed barriers.
> > 
> > let me repeat this, the hci_usb driver is not worth fixing. Doing our  
> > own URB handling is a bad idea. The btusb driver should fix all of  
> > this. Only exception is that it is missing all the quirks, but that  
> > was me being lazy.
> > 
> 
> ok...  But as long as the old code is buildable and installable, we should
> fix bugs in it?

Yep.