James Cameron <quozl@xxxxxxxxxx> 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
