Re: [REGRESSION] 3.10.{6,7} crashes on network activity

["Arend van Spriel" <arend@broadcom.com>]

On 08/20/2013 10:36 AM, Tom Gundersen wrote:
> On Tue, Aug 20, 2013 at 4:15 PM, Arend van Spriel <arend@broadcom.com> wrote:
>> On 08/20/2013 06:56 AM, Felix Fietkau wrote:
>>>
>>> On 2013-08-20 2:28 AM, Greg Kroah-Hartman wrote:
>>>>
>>>> On Tue, Aug 20, 2013 at 08:26:11AM +0800, Tom Gundersen wrote:
>>>>>
>>>>> On Tue, Aug 20, 2013 at 8:03 AM, Greg Kroah-Hartman
>>>>> <gregkh@linuxfoundation.org> wrote:
>>>>>>
>>>>>> On Tue, Aug 20, 2013 at 07:59:47AM +0800, Tom Gundersen wrote:
>>>>>>>
>>>>>>> Hi guys,
>>>>>>>
>>>>>>> Starting with 3.10.6 (and still present in .7) I get an oops on
>>>>>>> connecting to the network.
>>>>>>>
>>>>>>> The attached picture shows the oops. In case it does not reach the ML,
>>>>>>> the top of the call trace reads:
>>>>>>>
>>>>>>> brcms_c_compute_rtscts_dur
>>>>>>> brcms_c_ampdu_finalize
>>>>>>> ampdu_finalize
>>>>>>> dma_txfast
>>>>>>> brcms_c_txfifo
>>>>>>> brcms_c_sendpkt_mac80211
>>>>>>> brcms_ops_tx
>>>>>>> __ieee80211_tx
>>>>>>>
>>>>>>> I bisected the problem and the first bad commit is
>>>>>>>
>>>>>>> commit ef47a5e4f1aaf1d0e2e6875e34b2c9595897bef6
>>>>>>> Author: Felix Fietkau <nbd@openwrt.org>
>>>>>>> Date:   Fri Jun 28 21:04:35 2013 +0200
>>>>>>>
>>>>>>>       mac80211/minstrel_ht: fix cck rate sampling
>>>>>>>
>>>>>>>       commit 1cd158573951f737fbc878a35cb5eb47bf9af3d5 upstream.
>>>>>>>
>>>>>>> Reverting it on top of .7 fixes the problem.
>>>>>>>
>>>>>>> I had the same (I suppose) problem on mainline some time ago, but I
>>>>>>> have not bisected it, verified that the problem still occurs there, or
>>>>>>> checked if reverting the upstream patch fixes it. I'd be happy to do
>>>>>>> that if it would help though.
>>>>>>>
>>>>>>> Let me know if you need any more information.
>>>>>>
>>>>>>
>>>>>> Do you have this same problem with 3.11-rc6 as well?
>>>>>
>>>>>
>>>>> Yes, I just confirmed. I also confirmed that reverting the mainline
>>>>> commit on top of -rc6 fixes the problem.
>>>>
>>>>
>>>> Great, thanks.
>>>>
>>>> Felix and Johannes, any chance we can get this reverted in Linus tree
>>>> soon, and push that revert back to the 3.10 stable tree as well?
>>>
>>> I'd like to avoid a revert, since that will simply replace one set of
>>> issues with another. Let's limit the use of the feature that brcmsmac
>>> can't handle to drivers that are known to work with it. Tom, Please
>>> test this patch to see if it fixes your issue.
>>
>>
>> Hi Felix,
>>
>> I have been diving into root causing why brcmsmac can not handle cck
>> fallback rates, because it should. Maybe it is better to flag no cck support
>> and only change brcmsmac.
>
> Hi Arend,
>
> In case you cannot reproduce, let me know if I can help with testing patches.

So far I have not been able to reproduce it. I have a patch to avoid the 
oops, but the transmit of the related frames will fail in the device so 
it is not a real fix. I will let you you know.

Regards,
Arend

> Cheers,
>
> Tom
>