Re: [PATCH] mac80211: fix crash with single-queue drivers

[Larry Finger <Larry.Finger@lwfinger.net>]

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.

Larry