On Fri, Nov 04, 2011 at 06:03:42PM +0100, Johannes Berg wrote:

On Tue, 2011-10-25 at 12:26 +0000, Linus Torvalds wrote:

quoted

On Tue, Oct 25, 2011 at 12:32 PM, David Miller [off-list ref] wrote:

quoted

The most visible thing in here is the reorganization of the drivers
under drivers/net.

Nope, the most visible thing are some new annoying warnings, that seem
absolutely broken.

At the very minimum, that WARN_ON(1) should be a WARN_ON_ONCE() or
something like that. Because showing it over an dover again is not
helpful.

Added the people who signed off on the changes to the affected files,
since they hopefully know why this happens and can fix it..

Sorry for the late reply.

I think this was actually caused by some changes from Ben Greear
"optimising" stuff in net/mac80211/work.c and keeping the wrong channel,
Stanislaw was also looking at this at some point I think. I agree that
it would be good to change to WARN_ON_ONCE(), will do that.

The warning itself has been around forever, but the fact that it
triggers now is probably related to the channel work & band switches.

I think this problem is related with linuxcon :-) and it is not current
regression, i.e. Ben's off-channel code was already committed in 3.0.
I have also RHEL6 - 2.6.32 bug report about that:
https://bugzilla.redhat.com/show_bug.cgi?id=749125

Probably there was something special on linuxcon wireless network (i.e.
big contention) what cause people start to see this warning. Eventually
nobody use wireless except conferences :-/

I have one pending patch which fix other instance of the warning (started
at ieee80211_tx_status()). I'll post it today. As Ben mentioned, two
fixes are pending in wireless-testing tree:

http://git.kernel.org/?p=linux/kernel/git/linville/wireless-testing.git;a=commitdiff;h=682ba5a44516529b29fc780c055e06104d36e31e
http://git.kernel.org/?p=linux/kernel/git/linville/wireless-testing.git;a=commitdiff;h=776308dd5fa8a41e8bbb79818a66bd68a7db757e 

However, I'm not sure if that cover all possible situations when
warning can be triggered. We need to do a careful review of channel
switching in mac80211.

Stanislaw