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Date:   Mon, 9 Jan 2023 11:03:55 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     JiaJie Ho <jiajie.ho@starfivetech.com>
Cc:     Olivia Mackall <olivia@selenic.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Emil Renner Berthing <kernel@esmil.dk>,
        Conor Dooley <conor.dooley@microchip.com>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>
Subject: Re: [PATCH v2 2/3] hwrng: starfive - Add TRNG driver for StarFive SoC
Message-ID: <Y7uEGxl8xJ1xxkKZ@gondor.apana.org.au>
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On Mon, Jan 09, 2023 at 02:58:14AM +0000, JiaJie Ho wrote:
>
> My trng device requires sending a generate new number cmd before each read.
> It then only populates the data registers with new random number and raise an interrupt when ready.
> If user choose to not wait, they will always get stale bits. 
> Is it okay to always return error if wait=false ?

What is the length of the wait time? Is there an upper bound?
What is the average wait time?

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt