James Cameron <qu...@laptop.org> writes:

> On Wed, Feb 14, 2018 at 04:26:42PM +0000, Jean Pierre TOSONI wrote:
>> ath9k returns a wrong RSSI value for frames received in a 30ms time
>> window after a channel change. The correct value is typically 10dB
>> below the returned value.
>
> How was your correct value determined?
>
>> This was found with a Atheros AR9300 Rev:3 chip (WLE350NX / JWX6083
>> cards), during offchannel scans.
>> 
>> Mark the signal value as invalid in this case.
>
> Why not adjust by 10dB?
>
> Speculating: in a typical card, RSSI is calculated by firmware from
> readings of ADCs attached to the receiver.  Firmware may average
> several readings.  Firmware may apply other offsets or calibrations,
> based on frequency and temperature.  This sounds like a firmware
> problem.

ath9k does not have firmware, only ath9k_htc has it.

-- 
Kalle Valo

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