Re: [PATCH] hw_random: Improve description of the ->read() interface

From: Herbert Xu
Date: Wed Aug 24 2016 - 09:13:35 EST


On Thu, Aug 18, 2016 at 01:37:21PM +0100, Daniel Thompson wrote:
> Currently, very few RNG drivers support single byte reads using the
> ->read() interface. Of the 14 drivers in drivers/char/hw_random that
> support this interface only three of these actually support max == 1.
> The other behaviours vary between return 0, return 2, return 4 and return
> -EIO).
>
> This is not a problem in practice because the core hw_random code never
> performs a read shorter than 16 bytes. The documentation for this function
> already contrains the alignment of the buffer pointer, so let's also
> guarantee that the buffer is at least as large as its alignment.
>
> This constraint is intended to be the weakest guarantee neccessary to
> allow driver writers to safely simplify their code.
>
> Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>

Patch applied. Thanks.
--
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