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Subject: Re: [PATCH] mt76: improve signal strength reporting
To:     Felix Fietkau <nbd@nbd.name>, linux-wireless@vger.kernel.org
References: <20220215125808.72378-1-nbd@nbd.name>
From:   Ben Greear <greearb@candelatech.com>
Organization: Candela Technologies
Message-ID: <9bb8329d-b2c7-139a-9f0d-a10bba3f4d8b@candelatech.com>
Date:   Tue, 15 Feb 2022 10:22:28 -0800
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On 2/15/22 4:58 AM, Felix Fietkau wrote:
> Instead of just taking the maximum per-chain signal strength values,
> add an approximation for the sum of the combined signal.
> This should more accurately reflect the real signal strength, especially
> if the per-chain signal strength values are close to each other

My concern with this patch is that many of the mtk radios do not provide enough
info to know how many RX chains are used when receiving a frame.  I think we should not
be summing more chains than the number of spatial streams received.

That said, this code may still be a closer estimate than existing code, and some
radios, like 7921 appear to report enough info by default to properly determine
the NSS count on a per frame basis.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com