Re: [PATCH v2 1/4] dt-bindindgs: i2c: qcom,i2c-geni: Document shared flag

[Mukesh Kumar Savaliya]

Thanks Krzysztof.

On 9/7/2024 2:34 PM, Krzysztof Kozlowski wrote:
> On 06/09/2024 21:14, Mukesh Kumar Savaliya wrote:
> > Adds qcom,shared-se flag usage. Use this when particular I2C serial
> > controller needs to be shared between two subsystems.
>
> <form letter>
> Please use scripts/get_maintainers.pl to get a list of necessary people
> and lists to CC (and consider --no-git-fallback argument). It might
> happen, that command when run on an older kernel, gives you outdated
> entries. Therefore please be sure you base your patches on recent Linux
> kernel.
>
> Tools like b4 or scripts/get_maintainer.pl provide you proper list of
> people, so fix your workflow. Tools might also fail if you work on some
> ancient tree (don't, instead use mainline) or work on fork of kernel
> (don't, instead use mainline). Just use b4 and everything should be
> fine, although remember about `b4 prep --auto-to-cc` if you added new
> patches to the patchset.
> </form letter>
>
> You already got this comment, so how many times it has to be repeated?
> Your process is just wrong if you do not use the tools for this.
Sorry, I was already using scripts/get_maintainer.pl but i kept everyone 
into To list (That's my mistake here). I shall keep maintainers in TO 
list and rest in CC list.

Question: With <Form Letter> , are you asking to add letter in this 
first patch ? I have cover letter, but it will get removed when patch 
gets merged. Please help suggest and clarify.
> > SE = Serial Engine, meant for I2C controller here.
> > TRE = Transfer Ring Element, refers to Queued Descriptor.
> >
> > Example :
> > Two clients from different SS can share an I2C SE for same slave device
>
> What is SS?
SS = Subsystem (EE - Execution Environment, can be Apps 
processor/TZ/Modem/ADSP etc). Let me add this too in next patch.
> > OR their owned slave devices.
> > Assume I2C Slave EEPROM device connected with I2C controller.
> > Each client from ADSP SS and APPS Linux SS can perform i2c transactions.
> > This gets serialized by lock TRE + DMA Transfers + Unlock TRE at HW level.
> >
> > Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@xxxxxxxxxxx>
> > ---
> >   Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> > index 9f66a3bb1f80..ae423127f736 100644
> > --- a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> > +++ b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml
> > @@ -60,6 +60,10 @@ properties:
> >     power-domains:
> >       maxItems: 1
> >   
> > +  qcom,shared-se:
> > +    description: True if I2C needs to be shared between two or more subsystems.
>
> What is a subsystem? With commit msg I still do not understand this.
SS = Subsystem (EE - Execution Environment, can be Apps 
processor/TZ/Modem/ADSP etc). Let me add EE too with full form.
> Maybe presence of hwlock defines it anyway, so this is redundant?
No, this flag is required. As hwlock comes into picture if this flag is 
defined. So flag is acting as a condition to take hwlock TRE 
descriptor(transfer ring element). Hope i could answer your query.
> Best regards,
> Krzysztof