From: Arjan van de Ven Date: Mon, 3 Jul 2006 07:25:36 +0000 (-0700) Subject: [PATCH] lockdep: annotate hostap netdev ->xmit_lock X-Git-Tag: v2.6.18-rc1~35 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd11acdd8542cb0c0fa7cd86590b1ba79d7e263a;p=linux-2.6 [PATCH] lockdep: annotate hostap netdev ->xmit_lock 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: [] dev_queue_xmit+0x120/0x24b > > but task is already holding lock: > (&dev->_xmit_lock){-+..}, at: [] 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 Cc: Arjan van de Ven Cc: "John W. Linville" Cc: Jeff Garzik Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c index b764cfda6e..dafaa5ff5a 100644 --- a/drivers/net/wireless/hostap/hostap_hw.c +++ b/drivers/net/wireless/hostap/hostap_hw.c @@ -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",