Re: [PATCH v2 2/2] ath9k: Fix STA disconnect issue due to received MIC failed bcast frames

[Ben Greear <greearb@candelatech.com>]

On 12/03/2010 06:17 AM, Senthil Balasubramanian wrote:
> On Fri, Dec 03, 2010 at 01:34:44PM +0530, Ben Greear wrote:
>> On 12/01/2010 11:16 PM, Mohammed Shafi wrote:
>>> On Thu, Dec 2, 2010 at 11:14 AM, Ben Greear<greearb@candelatech.com>   wrote:
>>>> On 12/01/2010 09:09 PM, Mohammed Shafi wrote:
>>>>>
>>>>> On Thu, Dec 2, 2010 at 1:28 AM, Ben Greear<greearb@candelatech.com>
>>>>>    wrote:
>>>>>>
>>>>>> On 12/01/2010 03:00 AM, Senthil Balasubramanian wrote:
>>>>>>>
>>>>>>> AR_RxKeyIdxValid will not be set for bcast/mcast frames and so relying
>>>>>>> this status for MIC failed frames is buggy.
>>>>>>>
>>>>>>> Due to this, MIC failure events for broadcast frames are not sent to
>>>>>>> supplicant resulted in AP disconnecting the STA.
>>>>>>>
>>>>>>> Able to pass Wifi Test case 5.2.18 with this fix.
>>>>>>
>>>>>> Please do not apply this yet.  As far as I can tell, either
>>>>>> of these patches breaks multiple VIF scenarios.  I'm not
>>>>>> sure exactly why, but I had to revert this to get any
>>>>>> of my interfaces to associate.
>>>>>
>>>>> Ben can you please give some more information(or just point out some
>>>>> link) regarding your test case,I can try it out.
>>>>> thanks,
>>>>> shafi
>>>>
>>>> Try this script, or something like it:
>>>>
>>>> http://www.spinics.net/lists/linux-wireless/msg60126.html
>>>>
>>>> Edit 'max' to create a small number of STA interfaces or you will probably
>>>> have
>>>> worse issues than them just not associating!
>>>>
>>>> You have to enable the nohwcrypt module option.
>>>>
>>>> Let me know if that doesn't work and I can probably put together something
>>>> more specific.
>>>
>>> thanks Ben.
>>
>> Were you able to reproduce the problem?
>
> I can reproduce this issue with single vif itself and with s/w crypt enabled.
>
> Can you please apply the v2 patch and try the following change on top of it in
>
> diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
> index 6c0c796..4871849 100644
> --- a/drivers/net/wireless/ath/ath9k/recv.c
> +++ b/drivers/net/wireless/ath/ath9k/recv.c
> @@ -1069,7 +1069,7 @@ static void ath9k_rx_skb_postprocess(struct ath_common *common,
>
>          keyix = rx_stats->rs_keyix;
>
> -       if ((is_mc || !(keyix == ATH9K_RXKEYIX_INVALID))&&  !decrypt_error&&
> +       if (!(keyix == ATH9K_RXKEYIX_INVALID)&&  !decrypt_error&&
>              ieee80211_has_protected(fc)) {
>                  rxs->flag |= RX_FLAG_DECRYPTED;
>          } else if (ieee80211_has_protected(fc)
>
> I haven't tested s/w crypto and this check causes mac80211 not to decrypt frames so it
> would have caused issues.. Can you please check this out? It wouldn't cause issues with
> h/w crypt. Please let me know whether it solves your issue.. It works for me.

I did a quick test and your -v2 patch plus this change appears to work fine.

Please note that you v2 patch would need some additional changes with the
above patch, because is_mc is no longer used in that method as far
as I can tell.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com