Re: on radio_enabled

[Kalle Valo <kalle.valo@iki.fi>]

Johannes Berg <johannes@sipsolutions.net> writes:

> Now, if we're going to use radio_enabled more, I wonder whether we
> should completely deconfigure the hardware when we want to turn off
> radio_enabled, and then completely reconfigure it once we enable the
> radio again.

I assume that you mean op_stop() and op_start() here.

> Pros:
>  * configures all hardware correctly without the driver needing to do
>    everything by itself
>  * works with all hardware for sure
>
> Cons:
>  * higher latency

>From stlc45xx and wl12xx perspective I would like to have low latency as
possible for the radio on/off case. This is what I had in mind:

interface down:

o chip is powered off while down
o ifup uploads firmware and initialises it
o ifup might take hundreds of milliseconds, at least with 1271

radio off:

o chip is powered on
o firmware possibly sleeping/hibernating
o radios turned off
o very low latency (<5 ms) to wakeup
o small power consuption during radio off

This way it would be possible to have a bit faster scans when not
associated (with radio off), but still have a possibility to completely
turn of chip from user space for a longer periods of time (with
interface down).

-- 
Kalle Valo