Messages in this thread | | | Date | Wed, 23 Nov 2011 20:55:57 +0100 | From | Jiri Slaby <> | Subject | Re: [RFC] cdc-acm: Fix potential deadlock (lockdep warning) |
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On 11/23/2011 07:53 PM, Havard Skinnemoen wrote: > --- a/drivers/usb/class/cdc-acm.c > +++ b/drivers/usb/class/cdc-acm.c ... > @@ -567,19 +574,10 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp) > > /* Perform the closing process and see if we need to do the hardware > shutdown */ > - if (!acm) > - return; > - > - mutex_lock(&open_mutex); > if (tty_port_close_start(&acm->port, tty, filp) == 0) {
Note that port->count is protected by port->lock usually. Till now it used to be protected by open_mutex in your driver. As of now it is not protected by anything. (Well, BTM is still there to save you, but...)
thanks, -- js suse labs
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