linux-kernel - Re: [PATCH v2 1/2] This patch adds a new device tree binding documentation.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250904-aromatic-loon-of-honeydew-f7861e@kuoka>
Date: Thu, 4 Sep 2025 10:26:30 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: 杨孙运 <yangsunyun1993@...il.com>
Cc: syyang <syyang@...tium.com>, robh@...nel.org, 
	Laurent.pinchart@...asonboard.com, andrzej.hajda@...el.com, conor+dt@...nel.org, 
	devicetree@...r.kernel.org, dri-devel@...ts.freedesktop.org, jernej.skrabec@...il.com, 
	jonas@...boo.se, krzk+dt@...nel.org, linux-kernel@...r.kernel.org, 
	neil.armstrong@...aro.org, rfoss@...nel.org
Subject: Re: [PATCH v2 1/2] This patch adds a new device tree binding
 documentation.

On Thu, Sep 04, 2025 at 04:08:30PM +0800, 杨孙运 wrote:
> > > +
> > > +description: |
> >
> > Do not need '|' unless you need to preserve formatting.
> >
> Both lontium,lt9211.yaml and lontium,lt9611.yaml use "|", so please
> confirm if they need to be removed.

Add code which is needed, not code which you found somewhere. Why '|' is
needed here?

> 
> > > +  The LT9611C are bridge devices which convert DSI to HDMI
> >
> > Why this cannot be added to lt9611 binding? Commit msg should clearly
> > answer that.
> >
> The lt9611 and lt9611c are chips of different specifications, and
> their related parameters are different.
> The VDD-supply of lt9611c is 1.2V; the vdd-supply of lt9611uxc is also
> 1.2V, while the vdd-supply of lt9611 is 1.8V.
> Now lt9611 and lt9611uxc are connected together. I'm not sure if this
> is a problem.
> If this lt9611c can also be bound to lt9611, and if you think it's
> okay, then I have no problem.

It is not a problem.

> 
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - lontium,lt9611c
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  "#sound-dai-cells":
> >
> > Missing dai-common ref.
> >
> I don't understand .   I referred to:
> Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
> Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> 


You call this device a DAI, so your binding should reference dai-common
schema, like every other one. You can check simple codecs for examples.


> > > +    const: 0
> > > +
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  reset-gpios:
> > > +    maxItems: 1
> > > +    description: GPIO connected to active high RESET pin.
> > > +
> > > +  vdd-supply:
> > > +    description: Regulator for 1.2V MIPI phy power.
> > > +
> > > +  vcc-supply:
> > > +    description: Regulator for 3.3V IO power.
> > > +
> > > +  ports:
> > > +    $ref: /schemas/graph.yaml#/properties/ports
> > > +
> > > +    properties:
> > > +      port@0:
> > > +        $ref: /schemas/graph.yaml#/properties/port
> > > +        description:
> > > +          Primary MIPI port-1 for MIPI input
> > > +
> > > +      port@1:
> > > +        $ref: /schemas/graph.yaml#/properties/port
> > > +        description:
> > > +          Additional MIPI port-2 for MIPI input, used in combination
> > > +          with primary MIPI port-1 to drive higher resolution displays
> > > +
> > > +      port@2:
> > > +        $ref: /schemas/graph.yaml#/properties/port
> > > +        description:
> > > +          HDMI port for HDMI output
> > > +
> > > +    required:
> > > +      - port@0
> > > +      - port@2
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - interrupts
> > > +  - vdd-supply
> > > +  - vcc-supply
> > > +  - ports
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/gpio/gpio.h>
> > > +    #include <dt-bindings/interrupt-controller/irq.h>
> > > +
> > > +    i2c10 {
> > > +      #address-cells = <1>;
> > > +      #size-cells = <0>;
> > > +
> > > +      hdmi-bridge@41 {
> > > +        compatible = "lontium,lt9611c";
> > > +        reg = <0x41>;
> > > +        #sound-dai-cells = <0>;
> > > +        interrupts-extended = <&pio 128 GPIO_ACTIVE_HIGH>;
> > > +        reset-gpios = <&pio 127 GPIO_ACTIVE_HIGH>;
> > > +        vdd-supply = <&lt9611_1v2>;
> > > +        vcc-supply = <&lt9611_3v3>;
> > > +        status = "okay";
> >
> > Nope, drop.
> >
> remove  status = "okay"  ?

Yes. Instead of asking me, you can try to think about possibilities.
Ask yourself yourself - why do you need it here? What changes if you
have it? What changes if you drop it? Why reviewer asks for it - maybe
there is something behind. That way you will learn more about this.

I suggest to go through the slides of my OSSE25 talk about DT for
beginners.

Best regards,
Krzysztof