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Message-ID: <b75b92bf64b55ba0ace0fbff65955c838a294dec.camel@dylanvanassche.be>
Subject: Re: [PATCH 1/2] dt-bindings: misc: qcom,fastrpc: add
 qcom,assign-all-memory property
From:   Dylan Van Assche <me@dylanvanassche.be>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Amol Maheshwari <amahesh@qti.qualcomm.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     Konrad Dybcio <konrad.dybcio@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org
Date:   Mon, 27 Mar 2023 13:37:03 +0200
In-Reply-To: <883c3c48-c6e5-556d-431f-e92592b9106a@linaro.org>
References: <20230325134410.21092-1-me@dylanvanassche.be>
         <20230325134410.21092-2-me@dylanvanassche.be>
         <883c3c48-c6e5-556d-431f-e92592b9106a@linaro.org>
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Hi Krzysztof,

On Sun, 2023-03-26 at 10:55 +0200, Krzysztof Kozlowski wrote:
> On 25/03/2023 14:44, Dylan Van Assche wrote:
> > Document the added qcom,assign-all-memory in devicetree bindings.
> >=20
> > Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
> > ---
> > =C2=A0Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml | 6
> > ++++++
> > =C2=A01 file changed, 6 insertions(+)
> >=20
> > diff --git
> > a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> > b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> > index 1ab9588cdd89..fa5b00534b30 100644
> > --- a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> > +++ b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> > @@ -57,6 +57,12 @@ properties:
> > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Virtual machine IDs for remote pro=
cessor.
> > =C2=A0=C2=A0=C2=A0=C2=A0 $ref: "/schemas/types.yaml#/definitions/uint32=
-array"
> > =C2=A0
> > +=C2=A0 qcom,assign-all-mem:
> > +=C2=A0=C2=A0=C2=A0 description:
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Assign memory to all Virtual machines d=
efined by qcom,vmids.
>=20
> This (neither commit msg) does not explain why this is needed and
> actually does not sound like hardware-related property.

This is made a separate property to toggle different behavior in the
driver if it is needed for some FastRPC nodes. Downstream does guard
this with a property 'restrict-access' as well, see [1] for a random
SDM845 downstream kernel. On SDM845, this property is not present, thus
the IF block runs. On SDM670, this property is present, then the IF
block is skipped. That's why I opt for this property to have this
behaviour conditionally. I'm not sure how to explain it better though.

Any feedback is appreciated, thanks!

Kind regards,
Dylan Van Assche

[1]
https://github.com/SHIFTPHONES/android_kernel_shift_sdm845/blob/sos-3.x/dri=
vers/char/adsprpc.c#L4615-L4631

>=20
> > +=C2=A0=C2=A0=C2=A0 type: boolean
> > +
> > +
>=20
> Do not add double blank lines.
>=20
> > =C2=A0=C2=A0 "#address-cells":
> > =C2=A0=C2=A0=C2=A0=C2=A0 const: 1
> > =C2=A0
>=20
> Best regards,
> Krzysztof
>=20