lkml.org 
[lkml]   [2006]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [patch] lockdep, annotate slocks: turn lockdep off for them
From
Date
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.

Can you test the patch below?

---
drivers/net/wireless/hostap/hostap_hw.c | 10 ++++++++++
1 file changed, 10 insertions(+)

Index: linux-2.6.17-mm4/drivers/net/wireless/hostap/hostap_hw.c
===================================================================
--- linux-2.6.17-mm4.orig/drivers/net/wireless/hostap/hostap_hw.c
+++ linux-2.6.17-mm4/drivers/net/wireless/hostap/hostap_hw.c
@@ -3096,6 +3096,14 @@ static void prism2_clear_set_tim_queue(l
}


+/*
+ * 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)
@@ -3260,6 +3268,8 @@ 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",

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-07-02 00:10    [W:0.118 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site