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Date:   Wed, 27 Apr 2022 16:24:39 -0500
From:   Rob Herring <robh@kernel.org>
To:     Detlev Casanova <detlev.casanova@collabora.com>
Cc:     linux-kernel@vger.kernel.org, arnd@arndb.de,
        bcm-kernel-feedback-list@broadcom.com, devicetree@vger.kernel.org,
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Subject: Re: [RFC PATCH v2 2/3] of: Add support for -@ when compiling overlays
Message-ID: <Ymm0l2/oGpt/SeDO@robh.at.kernel.org>
References: <20220427185243.173594-1-detlev.casanova@collabora.com>
 <20220427185243.173594-3-detlev.casanova@collabora.com>
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On Wed, Apr 27, 2022 at 02:52:42PM -0400, Detlev Casanova wrote:
> This commit adds an option to compile all device trees with -@ to add the
> symbol table to the Device Tree Blobs.

Why would we want to tie this to the kernel config?

Globally enabling it has already been discussed and rejected.

> It prepares the introduction of device tree overlays that are
> not applied on device trees at compile time (dtbo files.)
> 
> These device tree overlays will be used by either a bootloader or a
> linux userspace tool to extend the base device tree.
> 
> This is used e.g. for drivers that need device tree nodes for optional
> non plug and play devices, like an external DSI touchscreen panel that
> embeds different i2c devices to control it.

You can already set DTC_FLAGS per directory (and target?), so enable it 
for the dtbs that have overlays.

> 
> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
> ---
>  drivers/of/Kconfig   | 8 ++++++++
>  scripts/Makefile.lib | 9 +++++++--
>  2 files changed, 15 insertions(+), 2 deletions(-)