[U-Boot] [PATCH] sunxi: fix DCDC2 output in CHIP_defconfig

Maxime Ripard
2016-03-08T22:18:43Z

On Mon, Mar 07, 2016 at 03:50:11PM +0200, Siarhei Siamashka wrote:
> On Mon, 7 Mar 2016 13:44:11 +0100
> Maxime Ripard <maxime.ripard@free-electrons.com> wrote:
>
> > From: Boris Brezillon <boris.brezillon@free-electrons.com>
> >
> > Unlike the datasheet recommendation, the R8 SoC requires a 1.4V supply
> > for its CPU when operating at 1Ghz.
>
> That's interesting. Is this R8 SoC datasheet with the Allwinner
> recommended cpufreq operating points available in public access
> somewhere?

Yeah:
https://github.com/NextThingCo/CHIP-Hardware/tree/master/CHIP%5Bv1_0%5D/CHIPv1_0-BOM-Datasheets

But note that it's the usual datasheet from Allwinner, you don't have
a list of operating points.

> Are they really recommending 1008MHz @1.3V there?

It was a misunderstanding on our side. We thought that the nominal
tension was the recommended one, and our prototypes were running just
fine with it. Later samples (probably from a different batch) turned
out to have memory corruptions because of the lower voltage.

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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