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Subject: Re: [PATCH v3 1/1] wcn36xx: Add RX frame SNR as a source of system
 entropy
From:   Kalle Valo <kvalo@kernel.org>
In-Reply-To: <20220915004117.1562703-2-bryan.odonoghue@linaro.org>
References: <20220915004117.1562703-2-bryan.odonoghue@linaro.org>
To:     Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc:     loic.poulain@linaro.org, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, wcn36xx@lists.infradead.org,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        bryan.odonoghue@linaro.org, "Jason A . Donenfeld" <Jason@zx2c4.com>
User-Agent: pwcli/0.1.1-git (https://github.com/kvalo/pwcli/) Python/3.7.3
Message-ID: <166359136168.17652.16916114902781460375.kvalo@kernel.org>
Date:   Mon, 19 Sep 2022 12:42:43 +0000 (UTC)
Precedence: bulk

Bryan O'Donoghue <bryan.odonoghue@linaro.org> wrote:

> The signal-to-noise-ratio SNR is returned by the wcn36xx firmware for each
> received frame. SNR represents all of the unwanted interference signal
> after filtering out the fundamental frequency and harmonics of the
> frequency.
> 
> Noise can come from various electromagnetic sources, from temperature
> affecting the performance hardware components or quantization effects
> converting from analog to digital domains.
> 
> The SNR value returned by the WiFi firmware then is a good source of
> entropy.
> 
> Other WiFi drivers offer up the noise component of the FFT as an entropy
> source for the random pool e.g.
> 
> commit 2aa56cca3571 ("ath9k: Mix the received FFT bins to the random pool")
> 
> I attended Jason's talk on sources of randomness at Plumbers and it
> occurred to me that SNR is a reasonable candidate to add.
> 
> Cc: Jason A. Donenfeld <Jason@zx2c4.com>
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Patch applied to ath-next branch of ath.git, thanks.

e1a6b5d3a971 wifi: wcn36xx: Add RX frame SNR as a source of system entropy

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20220915004117.1562703-2-bryan.odonoghue@linaro.org/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches