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[PATCH] lockdep: annotate hostap netdev ->xmit_lock

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On Fri, 2006-06-30 at 15:45 -0700, Miles Lane wrote:
> Okay, I rebuilt my kernel with your combo patch applied.
> Then, I inserted my US Robotics USR2210 PCMCIA wifi card,
> ran "pccardutil eject", popped out the card and then inserted
> a Compaq iPaq wifi card.  This triggered the following.
>
> [ INFO: possible circular locking dependency detected ]
> -------------------------------------------------------
> syslogd/1886 is trying to acquire lock:
>  (&dev->queue_lock){-+..}, at: [<c11a50b5>] dev_queue_xmit+0x120/0x24b
>
> but task is already holding lock:
>  (&dev->_xmit_lock){-+..}, at: [<c11a5118>] dev_queue_xmit+0x183/0x24b
>
> which lock already depends on the new lock.

ok this appears to be hostap playing games... it has 2 network devices
for one piece of hardware and one calls the other via the networking
layer; there is thankfully a natural ordering between the two, so just
making the slave one a separate type ought to make this work.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Arjan van de Ven 2006-07-03 00:25:36 -07:00 committed by Linus Torvalds
parent a5b5bb9a05
commit cd11acdd85
1 changed files with 10 additions and 0 deletions
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10
drivers/net/wireless/hostap/hostap_hw.c
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@ -3095,6 +3095,14 @@ static void prism2_clear_set_tim_queue(local_info_t *local)
}
/*
* HostAP uses two layers of net devices, where the inner
* layer gets called all the time from the outer layer.
* This is a natural nesting, which needs a split lock type.
*/
static struct lock_class_key hostap_netdev_xmit_lock_key;
static struct net_device *
prism2_init_local_data(struct prism2_helper_functions *funcs, int card_idx,
struct device *sdev)
@ -3259,6 +3267,8 @@ while (0)
SET_NETDEV_DEV(dev, sdev);
if (ret >= 0)
ret = register_netdevice(dev);
lockdep_set_class(&dev->_xmit_lock, &hostap_netdev_xmit_lock_key);
rtnl_unlock();
if (ret < 0) {
printk(KERN_WARNING "%s: register netdevice failed!\n",