[ath9k-devel] Linksys WPC300N Wireless-N Notebook Adapter

[Luis R. Rodriguez <lrodriguez@atheros.com>]

On Mon, May 18, 2009 at 10:43 AM, Johannes Berg
<johannes@sipsolutions.net> wrote:
> On Mon, 2009-05-18 at 10:33 -0700, Luis R. Rodriguez wrote:
>
>> defined properly. If there is some enhancement to this reporting which
>> you can think of please feel free to address this on linux-wireless
>> with your recommendation. The next best thing we have to report
>> signal would be through using the RCPI concept [1], but note that it
>> specifically defines it as "the received RF power in the channel measured
>> over the entire received frame or by other equivalent means which meet the
>> specified accuracy". The last part is a little vague, that of
>> "or by other equivalent means which meet the specified accuracy" and
>> its questionable whether or not all devices support this. Anyway
>> this could just be used by userspace and nl80211 should not have to know
>> about this except maybe whether or not the device claims to support
>> this accuracy terminology, I am also not sure what the status of 802.11k
>> is which the group working on this, so it may be premature to just add
>> it to nl80211/cfg80211.
>
> I think that's a red herring -- dBm display should be good enough or
> better than rcpi?

Yeah I think for now its more than enough. Since we are reporting dBm
userspace could just parse this in terms of RCPI if it wanted to. RCPI
seems to require an actual accuracy and I don't think any vendor is
adhering to it yet.

>> Patches are welcomed to add tx power displaying, not sure why we didn't
>> add that.
>
> I don't think TX power is per station?

Oh true. Except unless the user users something like radiotap to
inject desired tx power for each station.

> We currently display max tx power
> per channel -- which is also what we use if iwconfig (wext) is set to
> auto and we don't have 11h info. But I'm not sure in what form we should
> display this since it changes per channel etc.

Fine by me. I suspect packet injection with radiotap and reporting the
last used tx power for a station would be used mostly by experimenters
and for that case a patch is welcomed but we'd then need to add this
to the station struct in mac80211 and keep track of it and export it.
Not sure if its worth it.

  Luis