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Date:   Wed, 3 Feb 2021 11:19:14 +0100
From:   Boris Brezillon <boris.brezillon@collabora.com>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>, richard@nod.at,
        vigneshr@ti.com, linux-mtd@lists.infradead.org,
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        bjorn.andersson@linaro.org
Subject: Re: [PATCH] mtd: rawnand: Do not check for bad block if bbt is
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On Wed, 03 Feb 2021 15:42:02 +0530
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote:

> >> 
> >> I got more information from the vendor, Telit. The access to the 3rd  
> >partition is protected by Trustzone and any access in non privileged
> >mode (where Linux kernel runs) causes kernel panic and the device
> >reboots. 

Out of curiosity, is it a per-CS-line thing or is this section
protected on all CS?

> >
> >Ok, so this is not a chip feature but more a host constraint.
> >
> >In this case it would be a good idea to add a host DT property which
> >describes the zone to avoid accessing it. Something like:
> >
> >	secure-area/secure-section = <start length>;
> >
> >From the core perspective, we should parse this property early enough
> >and return -EIO when trying to access this area.

FWIW, I'm not sure making it part of the core is a good idea, at least
not until we have a different platform with a same needs. The
controller driver can parse it and return -EACCESS (or -EIO) when this
section is accessed.