RE: [EXT] Re: [PATCH v4 2/2] dt-bindings: media: imx-jpeg: Assign slot for imx jpeg encoder/decoder

[Ming Qian]

>From: Rob Herring <robh@xxxxxxxxxx>
>Sent: 2023年9月29日 0:47
>To: Ming Qian <ming.qian@xxxxxxx>
>Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>; Mirela Rabulea (OSS)
><mirela.rabulea@xxxxxxxxxxx>; shawnguo@xxxxxxxxxx;
>krzysztof.kozlowski+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx;
>mchehab@xxxxxxxxxx; hverkuil-cisco@xxxxxxxxx; s.hauer@xxxxxxxxxxxxxx;
>kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; X.H. Bao
><xiahong.bao@xxxxxxx>; Eagle Zhou <eagle.zhou@xxxxxxx>; Tao Jiang
><tao.jiang_2@xxxxxxx>; dl-linux-imx <linux-imx@xxxxxxx>;
>devicetree@xxxxxxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx; linux-
>kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>Subject: Re: [EXT] Re: [PATCH v4 2/2] dt-bindings: media: imx-jpeg: Assign slot
>for imx jpeg encoder/decoder
>
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>On Wed, Sep 27, 2023 at 09:10:52AM +0000, Ming Qian wrote:
>> >From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
>> >
>> >On 26/09/2023 12:10, Ming Qian wrote:
>> >> There are total 4 slots available in the IP, and we only need to
>> >> use one slot in one os, assign a single slot, configure interrupt
>> >> and power domain only for 1 slot, not for the all 4 slots.
>> >>
>> >> Signed-off-by: Ming Qian <ming.qian@xxxxxxx>
>> >> ---
>> >> v4
>> >> - improve commit message
>> >> - don't make an ABI break
>> >> v3
>> >> - add vender prefix, change property slot to nxp,slot
>> >> - add type for property slot
>> >>
>> >>  .../bindings/media/nxp,imx8-jpeg.yaml         | 45 +++++++++----------
>> >>  1 file changed, 21 insertions(+), 24 deletions(-)
>> >>
>> >> diff --git
>> >> a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
>> >> b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
>> >> index 3d9d1db37040..4bcfc815c894 100644
>> >> --- a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
>> >> +++ b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml
>> >> @@ -32,19 +32,26 @@ properties:
>> >>      maxItems: 1
>> >>
>> >>    interrupts:
>> >> -    description: |
>> >> -      There are 4 slots available in the IP, which the driver may use
>> >> -      If a certain slot is used, it should have an associated interrupt
>> >> -      The interrupt with index i is assumed to be for slot i
>> >> -    minItems: 1               # At least one slot is needed by the driver
>> >> -    maxItems: 4               # The IP has 4 slots available for use
>> >> +    description:
>> >> +      Interrupt number for slot
>> >> +    maxItems: 1
>> >>
>> >>    power-domains:
>> >>      description:
>> >>        List of phandle and PM domain specifier as documented in
>> >>        Documentation/devicetree/bindings/power/power_domain.txt
>> >> -    minItems: 2               # Wrapper and 1 slot
>> >> -    maxItems: 5               # Wrapper and 4 slots
>> >> +    minItems: 1               # VPUMIX
>> >> +    maxItems: 2               # Wrapper and 1 slot
>> >> +
>> >> +  nxp,slot:
>> >> +    $ref: /schemas/types.yaml#/definitions/uint32
>> >> +    description:
>> >> +      Integer number of slot index used. There are 4 slots available in the
>IP,
>> >> +      and driver can use a certain slot, it should have an associated
>interrupt
>> >> +      and power-domain. In theory, it supports 4 os or vm. If not specified,
>0
>> >> +      is used by default.
>> >> +    minimum: 0
>> >> +    maximum: 3
>> >
>> >NAK, you still did not answer concerns why this is needed and justified.
>> >I keep asking and you keep ignoring...
>> >
>> >Best regards,
>> >Krzysztof
>>
>> Hi Krzysztof,
>>
>> > Nothing explains what is a slot and nothing explains why do you need this
>property.
>>
>> I thought I had answered that question, but seems you don't agree with that
>explanation.
>> Would the following description be any better?
>>
>> The slot is the IP used to share the jpeg engine across multiple VMS
>> and os, there are 4 slots available in the IP. We can use one slot in
>> linux. The slot index indicates which slot we choose. If not
>> specified, 0 is used by default.
>

Hi Rob

>If you have to modify the DT to update 'nxp,slot', then you can modify the DT
>to just expose the parts of the h/w for the assigned slot. For example, only put
>slot 1's power-domains entry in the DT when slot 1 is assigned.
>

That's what this patch is trying to do. 
What should I do next?
Prepare the next version patch and modify the commit message after reaching an agreement?

>As far as formatting your emails, talk to your NXP colleagues. They've figured it
>out. If you've configured git-send-email successfully, then using mutt should
>be possible. You can use 'b4' to get the thread mbox, and read it in mutt.
>
>Rob

I'll talk with someone in nxp, and I'll try to use mutt.
Thanks for your advice.

Best regards,
Ming