Message-ID: <1341584069.16893.5.camel@jlt3.sipsolutions.net> (sfid-20120706_161440_033438_4F554A2F)
Subject: Re: [PATCH] mac80211: fix crash with single-queue drivers
From: Johannes Berg <johannes@sipsolutions.net>
To: Larry Finger <Larry.Finger@lwfinger.net>
Cc: linux-wireless@vger.kernel.org
Date: Fri, 06 Jul 2012 16:14:29 +0200
In-Reply-To: <4FF6F231.8040300@lwfinger.net> (sfid-20120706_161207_104974_E56E6B8F)
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On Fri, 2012-07-06 at 09:12 -0500, Larry Finger wrote:
> On 07/06/2012 08:26 AM, Johannes Berg wrote:
> > On Fri, 2012-07-06 at 08:15 -0500, Larry Finger wrote:
> >> On 07/04/2012 05:53 AM, Johannes Berg wrote:
> >>> From: Johannes Berg <johannes.berg@intel.com>
> >>>
> >>> Larry (and some others I think) reported that with
> >>> single-queue drivers mac80211 crashes when waking
> >>> the queues. This happens because we allocate just
> >>> a single queue for each virtual interface in case
> >>> the driver doesn't have at least 4 queues, but the
> >>> code stopping/waking the virtual interface queues
> >>> wasn't taking this into account.
> >>>
> >>> Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
> >>> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> >>> ---
> >>>    net/mac80211/util.c |   12 ++++++++++--
> >>>    1 file changed, 10 insertions(+), 2 deletions(-)
> >>
> >> Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
> >>
> >> This patch fixes the problem for drivers that always report a single queue such
> >> as at76c503-usb.
> >
> > Thanks, I'll merge this.
> >
> >>   There is still a problem for b43 with open-source firmware
> >> where the number of queues changes from 4 to 1. As that only affects b43, do you
> >> agree that the problem should be fixed there?
> >
> > Yes, b43 confuses me a bit. We were looking at this a few weeks ago, but
> > I couldn't figure out how to solve it.
> >
> > I think for b43 the solution should be to check if it's proprietary or
> > free firmware before registering with mac80211, then to mac80211 it's
> > really just either 1 or 4, not changing.
> 
> I agree with that solution, and I will try to implement that model.

My think my last attempt was this:
http://p.sipsolutions.net/e45e57bbc9509e69.txt

Andre reported it didn't work though.

johannes