[RFC 2/2] ath10k: add spectral scan feature

[Michal Kazior]

On 16 July 2014 16:35, Sven Eckelmann <sven at narfation.org> wrote:
> On Wednesday 16 July 2014 11:30:12 Michal Kazior wrote:
[...]
>>
>> What happens when an interface is removed without spectral scan being
>> stopped?
>
> This is a question for the QCA firmware guys.

Not really. My problems is this:
 - have 2 interfaces (vdev 0 and vdev 1)
 - start spectral (using vdev 0 which happens to be the first one)
 - remove 1 interface (vdev 0)

Now spectral scan on vdev 0 is not stopped and if you request to stop
it you effectively call spectral commands with vdev 1 (the other
interface which is the only one left). Yuck. I don't even want to know
how firmware (or different versions and branches of it) handle this
clumsiness.


>> > +int ath10k_spectral_scan_config(struct ath10k *ar, enum spectral_mode
>> > mode) +{
>> > +       int count, ret;
>>
>> We tend to use `res` in ath10k.
>
> Thanks, will be changed. But actually, I found a lot of ret stuff in the
> ath10k code.

Ah, sorry. You're right. I had a brain fart. `ret` is good.


[...]
>> > +       __be16 freq1;
>> > +       __be16 freq2;
>> > +       __be16 noise;
>> > +       __be16 max_magnitude;
>> > +       __be16 total_gain_db;
>> > +       __be16 base_pwr_db;
>> > +       __be64 tsf;
>> > +       s8 max_index;
>> > +       u8 rssi;
>> > +       u8 relpwr_db;
>> > +       u8 avgpwr_db;
>> > +
>> > +       u8 data[SPECTRAL_ATH10K_HT20_NUM_BINS];
>>
>> And as pointed out the size/count of bins is most likely not
>> bandwidth-dependant. It's just a matter of resolution configured with
>> fft_size + bin_scale. Maybe this should be a variable-sized array?
>
> Ok, bin_scale didn't make a difference in my tests (I've just repeated them).
> But 2 ** (fft_size - 1) seems to be relevant. We have to change the format
> accordingly.
>
> But currently we don't see any change in the bandwidth (20MHz/40MHz) for the
> different bin numbers. This has to be checked later in detail.

Yes. Apparently number of bins does *not* change with bandwidth but in
that case I'm guessing bin data does refer to the given bandwidth
which implies different bandwidths end up with different bin data
*resolution*.


Michał