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Date:   Thu, 28 Jul 2022 12:33:47 +0100
From:   Sudeep Holla <sudeep.holla@arm.com>
To:     Maximilian Luz <luzmaximilian@gmail.com>
Cc:     Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Steev Klimaszewski <steev@kali.org>,
        Shawn Guo <shawn.guo@linaro.org>,
        Cristian Marussi <cristian.marussi@arm.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-msm@vger.kernel.org, linux-efi@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] dt-bindings: firmware: Add Qualcomm UEFI Secure
 Application client
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On Thu, Jul 28, 2022 at 12:48:19PM +0200, Maximilian Luz wrote:

[...]

>
> I would very much like to avoid the need for special bootloaders. The
> devices we're talking about are WoA devices, meaning they _should_
> ideally boot just fine with EFI and ACPI.
>

Completely agreed.

> From an end-user perspective, it's annoying enough that we'll have to
> stick with DTs for the time being due to the use of PEPs in ACPI.

But have we explored or investigated what it takes to rewrite ACPI f/w
to just use standard methods ? Does it require more firmware changes or
new firmware entities or impossible at any cost ?

For me that is more important than just getting this one on DT. Because
if you take that path, we will have to keep doing that, with loads of
unnecessary drivers if they are not shared with any other SoC with DT
support upstream. We might also miss chance to get things added to the ACPI
spec as we don't care which means that we never be able to use ACPI on
similar future platforms even though they get shipped with ACPI.

It will be a loop where we constantly keep converting this ACPI shipped
platform into DT upstream. IMHO we don't want to be there.

--
Regards,
Sudeep