linux-kernel - Re: [PATCH] um: Rewrite host RNG driver.

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Message-ID: <CAFLxGvyiviQxr_Bj57ibTU4DQ1H5wQC4DE5DNFBtAFoohcgbsg@mail.gmail.com>
Date:   Thu, 29 Aug 2019 15:26:24 +0200
From:   Richard Weinberger <richard.weinberger@...il.com>
To:     Alexander Neville <dark@...atile.bz>
Cc:     Richard Weinberger <richard@....at>,
        Anton Ivanov <anton.ivanov@...bridgegreys.com>,
        linux-um@...ts.infradead.org, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] um: Rewrite host RNG driver.

On Thu, Aug 29, 2019 at 3:45 AM Alexander Neville <dark@...atile.bz> wrote:
>
> The old driver had a bug that would cause it to outright stop working if
> the host's /dev/random were to block. Instead of trying to track down
> the cause of said bug, rewriting it from scratch turned out to be a much
> better option as it came with a few benefits:
>
>  - The new driver properly registers itself as an hardware RNG.
>
>  - The code is simpler and therefore easier to maintain.
>
>  - It serves as a minimal example of writing a hardware RNG driver.
>
> I also edited the Kconfig symbol to bring it up to more modern
> standards.

So, you removed -EAGAIN handling, made everything synchronous,
and changed the interface.
I'm not sure if this really a much better option.

Rewriting the driver in a modern manner is a good thing, but throwing the
old one way with a little hand weaving just because of a unspecified issue
is a little harsh.
Can you at lest provide more infos what problem you're facing with the
old driver?

-- 
Thanks,
//richard