Re: [PATCH] backports: mac80211: revert to old stats behaviour for older kernels

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

On 05/04/15 09:43, Johannes Berg wrote:
> On Sun, 2015-05-03 at 21:49 +0200, Arend van Spriel wrote:
>
>> I don't either, but I had a bunch of test systems that I wanted to get
>> going.
>
> While on vacation? :)

It happened just before as such things tend to do. There is probably 
some law for this ;-)

>>> What part of this isn't supported? Is there no pointer whatsoever that
>>> we can use? We still implement the ndo_getstats64 [or whatever it's
>>> called] ourselves anyway, so we don't really use any API here apart from
>>>    * netdev_alloc_pcpu_stats, which is trivially backported
>>>    * dev->tstats, which is just a single pointer and we could use anything
>>> else,
>>>      even perhaps in sdata
>>
>> I have to learn about the per-cpu operations someday so why not now
>> while spending two weeks vacation ;-)
>
> Heh. Go enjoy your vacation, I can handle this :)

no doubt.

> I think you arrived at kernel 3.14 due to 8f84985fec10d. However, I
> think we can just do the following
>
>   * backport "struct pcpu_sw_netstats" (needed on<  3.14)
>   * backport "netdev_alloc_pcpu_stats" (needed on<  3.15)
>   * make an spatch replacing dev->tstats with ((struct pcpu_sw_netstats *)dev->ml_priv)
>     (since ml_priv has existed for a long time, and they're in a union)

That will work. Guess you will drop the mac80211 patch I sent using 
sdata instead. Fine by me.

Regards,
Arend