Re: [PATCH] ath9k_htc: update RSSI values only when the device is associated

[Felix Fietkau <nbd@openwrt.org>]

On 2013-02-01 1:50 PM, Bernhard Urban wrote:
> add an if-guard, otherwise iw(8) reports weird signal strengths.
> 
> The behaviour was fine before this commit:
> 	7c277349ecbd66e19fad3d949fa6ef6c131a3b62
> Therefore, this patch is a partially revert of it.
I think your commit message is a bit misleading. The main problem with
signal strength reporting is not that it's missing some checks for if
the device is associated, or if the received frame is a local beacon.

The main problem is in these lines below:
> +		if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER)) {
> +			s8 rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
> +			rxbuf->rxstatus.rs_rssi = rssi;
> +		}
It does not make any sense to update the per-frame RSSI value with any
sort of average. ath9k filters out invalid RSSI values by ignoring rssi
for ANI when rx_stats->rs_moreaggr is set. In that case it also sets the
RX_FLAG_NO_SIGNAL_VAL flag to tell mac80211 to ignore the value for its
own signal strength averages.

- Felix