Re: [PATCH v2] ARM: dts: sunxi: Add sid for a83t

From: Maxime Ripard <maxime.ripard@free-electrons.com>
To: Emmanuel Vadot <manu@bidouilliste.com>
Cc: Kyle Evans <kevans91@ksu.edu>,
	Mark Rutland <mark.rutland@arm.com>,
	devicetree@vger.kernel.org, linux-sunxi@googlegroups.com,
	Russell King <linux@armlinux.org.uk>,
	linux-kernel@vger.kernel.org, Chen-Yu Tsai <wens@csie.org>,
	Rob Herring <robh+dt@kernel.org>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] ARM: dts: sunxi: Add sid for a83t
Date: Fri, 22 Dec 2017 09:35:08 +0100	[thread overview]
Message-ID: <20171222083508.dfcp6egfvxykmogg@flea.lan> (raw)
In-Reply-To: <20171221190903.56ebae536acf51401c63802c@bidouilliste.com>

[-- Attachment #1: Type: text/plain, Size: 1888 bytes --]

On Thu, Dec 21, 2017 at 07:09:03PM +0100, Emmanuel Vadot wrote:
> 
>  Hi Maxime,
> 
> On Thu, 21 Dec 2017 16:26:30 +0100
> Maxime Ripard <maxime.ripard@free-electrons.com> wrote:
> 
> > Hi,
> > 
> > On Thu, Dec 21, 2017 at 09:19:24AM -0600, Kyle Evans wrote:
> > > On Thu, Dec 21, 2017 at 8:55 AM, Maxime Ripard
> > > <maxime.ripard@free-electrons.com> wrote:
> > > > Hi Kyle,
> > > >
> > > > On Tue, Dec 19, 2017 at 03:05:23PM -0600, kevans91@ksu.edu wrote:
> > > >> Allwinner a83t has a 1 KB sid block with efuse for security rootkey and
> > > >> thermal calibration data, add node to describe it.
> > > >>
> > > >> a83t-sid is not currently supported by nvmem/sunxi-sid, but it is
> > > >> supported in an external driver for FreeBSD.
> > > >>
> > > >> Signed-off-by: Kyle Evans <kevans91@ksu.edu>
> > > >
> > > > The patch looks fine in itself, but we've had a number of issues with
> > > > the register layout (and access patterns) in the past, so I'd rather
> > > > have something that works in Linux too if possible.
> > > 
> > > I have a patch that I think should make it work fine on Linux [1], but
> > > I'm afraid I have little to no capability to test it myself and so I
> > > did not add it as well.
> > > 
> > > I do know that the rootkey is offset 0x200 into the given space [2],
> > > as is the case with the H3, and that the readout quirk is not needed.
> > > I wasn't 100% sure that the a83t has 2Kbit worth of efuse space as the
> > > H3, but I do know that thermal data can be found at 0x34 and 0x38 in
> > > this space.
> > 
> > Then maybe we should leave it aside until someone takes some time on
> > the A83t. 
> 
>  Take some time on the Linux driver and do not apply this patch for
> now you mean ?

Yep.

Maxime

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

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]