Re: d80211 deadlock with wpa_supplicant and rmmod

On Thu, Jul 12, 2007 at 12:17:35AM +0100, seventh guardian wrote:

Hello,
First of all I'm fairly new to this list (in all, this is my first
message), so please be gentle.. I promise I will try not to waste your
precious time.

quoted

I believe we have a deadlock in d80211.

I have it too. But I'm using iwl3945 driver, in-kernel mac80211, and a
gentoo kernel (basically a patched vanilla-2.6.22.1). My machine is a
x86_64 core 2 duo.

quoted

The following triggers it on my 2way SMT machine with preempt.

modprobe bcm43xx-d80211
add sta0
ifconfig sta0 up
start wpa_supplicant on the interface
rmmod bcm43xx-d80211

After that rmmod hangs spinning and wpa_supplicant
stays in D state.

If I first kill wpa_supplicant and then rmmod the module,
it does not deadlock.

I can trigger this way:

modprobe iwl3945
ifconfig wlan0 up
start wpa_supplicant
do some wpa_supplicant work (for instance issue a scan)
stop wpa_supplicant

Then it will deadlock (that is, wpa_supplicant will refuse to be
killed). The same thing happens if I try to modprobe the module out
(modprobe will "hang spinning" as you said). I have to ultimately
hard-shutdown my machine to bring it back to normal.

It seems you are replying to a very old original message.  Since that
message was sent, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org has become the
primary forum for wireless discussion.

Any chance you are savvy enough with git to try the wireless-dev kernel?

        git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-dev.git

Can you replicate the problem using those sources?  If so, you may
want to attach your .config in your reply (just in case the exact
config makes a difference).

Thanks,

John
-- 
John W. Linville
linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org