Messages in this thread Patch in this message | | | From | AngeloGioacchino Del Regno <> | Subject | [RESEND PATCH] tpm: tpm_tis_spi_cr50: Add default RNG quality | Date | Wed, 27 Oct 2021 14:12:58 +0200 |
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To allow this device to fill the kernel's entropy pool at boot, setup a default quality for the hwrng found in Cr50.
After some testing with rngtest and dieharder it was, in short, discovered that the RNG produces fair quality randomness, giving around 99.93% successes in rngtest FIPS140-2.
Notably, though, when testing with dieharder it was noticed that the p-values distribution wasn't uniform in all the cases, so a conservative quality value was chosen.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> ---
Sorry for the resend, I forgot to include linux-kernel@vger.kernel.org the first time.
drivers/char/tpm/tpm_tis_spi_cr50.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/char/tpm/tpm_tis_spi_cr50.c b/drivers/char/tpm/tpm_tis_spi_cr50.c index ea759af25634..d6195fb58036 100644 --- a/drivers/char/tpm/tpm_tis_spi_cr50.c +++ b/drivers/char/tpm/tpm_tis_spi_cr50.c @@ -264,6 +264,7 @@ int cr50_spi_probe(struct spi_device *spi) phy = &cr50_phy->spi_phy; phy->flow_control = cr50_spi_flow_control; phy->wake_after = jiffies; + phy->priv.rng_quality = 700; init_completion(&phy->ready); cr50_phy->access_delay = CR50_NOIRQ_ACCESS_DELAY; -- 2.33.0
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