From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: [PATCH] dt-bindings: Add Google Widevine initialization parameters Date: Mon, 18 Sep 2023 14:03:50 +0200 Message-ID: References: <20230908101539.2622864-1-yich@google.com> <2ec056f3-e8a8-c5f3-b132-4b9d2beb616e@linaro.org> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1695038632; x=1695643432; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=J9ogOyEVxhw+nJiEoimMLZtN9S82zPQWJ0XXUiWbUVk=; b=G5s4rNEAMgVwENUq/aUJM26G0dGclr155UHwhkZP95mW1aL7LquZq1BgcGY37EVPwK hCP7CBBoV2ypaj98d7NV+fS3WXNFhOxl5nTaXMhopONO0h8qJVu1S6qlE9UAXpY5uMas iDAY2bE5YB+9s0rjOoLcvz+lEqnaKnYFAoybJKaPQbBw/kSwZHem4BjHqTtrDyBMgwNf UOdE0Ycs8SNeIG+ZgEelAuKKj+jzMFKmjgDMwAGBuWx1wAGSolRtNx8mnCT06Q9GpTmK 2ATJ/9JmoN1O7Yjc3MFoACiGTYfSyMjADcQf8DAfieRBXwziePBaysgDYSTjnH7VSneg RQbQ== List-Id: List-Subscribe: List-Unsubscribe: Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset="windows-1252" To: Yi Chou Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, krzysztof.kozlowski+dt-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-spec-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yich-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jens.wiklander-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, chenyian-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jkardatzke-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jwerner-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, sjg-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org On 18/09/2023 06:20, Yi Chou wrote: > On Sun, Sep 17, 2023 at 4:40=E2=80=AFPM Krzysztof Kozlowski > wrote: >> >> On 08/09/2023 12:15, Yi Chou wrote: >>> The necessary fields to initialize the widevine related functions in >>> OP-TEE. >>> >>> Signed-off-by: Yi Chou >>> Reviewed-by: Simon Glass >>> --- >>> .../bindings/options/google,widevine.yaml | 124 ++++++++++++++++++ >>> 1 file changed, 124 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/options/google,wi= devine.yaml >>> >>> diff --git a/Documentation/devicetree/bindings/options/google,widevine.= yaml b/Documentation/devicetree/bindings/options/google,widevine.yaml >>> new file mode 100644 >>> index 0000000000000..bf2b834cb1454 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/options/google,widevine.yaml >> >> There is no such hardware as "options". What is this supposed to be for? >> firmware? >=20 > These DT fields would not be consumed by the OS. > https://www.spinics.net/lists/devicetree-spec/msg01195.html > The previous discussion tended to use the "options" node. > Do we have any better place for these widevine related fields? I'll let Rob comment on this in such case. >=20 >> >>> @@ -0,0 +1,124 @@ >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/options/google,widevine.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: Google Widevine initialization parameters. >> >> This is a title, drop full stop. >=20 > Got it, will be fixed in the next patch. >=20 >> >>> + >>> +maintainers: >>> + - Jeffrey Kardatzke >>> + - Yi Chou >>> + >>> +description: >>> + The necessary fields to initialize the widevine related functions in >>> + OP-TEE. This node does not represent a real device, but serves as a >>> + place for passing data between firmware and OP-TEE. >>> + The public fields (e.g. tpm-auth-public-key & root-of-trust-cert) can >>> + be ignored because it's safe to pass the public information with the >>> + other methods(e.g. userland OP-TEE plugins). >> >> Then why isn't this a property of optee node? >=20 > Are you talking about the /firmware/optee node? > If I understand correctly, that node was talking about how the kernel > communicates with the OP-TEE. > But what we are doing here is passing some secrets from trusted > firmware into OP-TEE, and the data would not go through the linux > kernel. > I'm not sure if it is a good idea to mix two different purpose fields > in the same node... >=20 >> >>> + >>> +properties: >>> + compatible: >>> + const: google,widevine >> >> From the description I have no clue what is "widevine". The more >> surprising is to see it as "not hardware" but having its node and >> compatible, like it was a hardware node. >=20 > We already have a "chosen" node that is "not hardware" in the DT. > Should we just remove the compatible field from this node? >=20 > BTW, Widevine is a digital rights management (DRM) system to make sure > the video stream can only be decoded on the valid devices. Then describe it in the description. Best regards, Krzysztof