Re: [platforms: PATCH 1/8] Marvell/Armada: Implement EFI_RNG_PROTOCOL driver for EIP76 TRNG

[Leif Lindholm <leif.lindholm@linaro.org>]

On Thu, Oct 12, 2017 at 06:39:46AM +0200, Marcin Wojtas wrote:
> 2017-10-11 20:15 GMT+02:00 Ard Biesheuvel <ard.biesheuvel@linaro.org>:
> > On 11 October 2017 at 17:47, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> >> On Wed, Oct 11, 2017 at 05:40:42PM +0200, Marcin Wojtas wrote:
> >>> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >>> +    }
> >>> +    gBS->Stall (10);
> >>
> >> Why? Why 10? Please add a comment.
> >>
> >> No other comments on this patch.
> >>
> >
> > I don't remember the details, and I think the 1 ms delay was chosen
> > arbitrarily, but the purpose of the delay is to allow the hardware to
> > assume the 'ready' state.
> >
> 
> I don't have EIP150 docs, but how about a comment:
> 
> // Polling interval for obtaining TRNG data is 10us
> gBS->Stall (10);
> 
> I know it's not perfect, but would you accept it?:)

Nearly. "Polling interval ... is" sounds a bit too authoritative
(unless that is actually what is documented).
"Wait for more TRNG data to arrive" would be sufficient.

/
    Leif