Re: [PATCH v2 1/8] media: dt-bindings: qcom-kaanapali-iris: Add kaanapali video codec binding

[Vikash Garodia <vikash.garodia@oss.qualcomm.com>]

On 10/22/2025 12:45 AM, Krzysztof Kozlowski wrote:
> On 21/10/2025 20:55, Vikash Garodia wrote:
>>
>> On 10/18/2025 9:28 PM, Krzysztof Kozlowski wrote:
>>> On 17/10/2025 16:16, Vikash Garodia wrote:
>>>> +  clock-names:
>>>> +    items:
>>>> +      - const: iface
>>>> +      - const: core
>>>> +      - const: vcodec0_core
>>>> +      - const: iface1
>>>> +      - const: core_freerun
>>>> +      - const: vcodec0_core_freerun
>>>> +      - const: vcodec_bse
>>>> +      - const: vcodec_vpp0
>>>> +      - const: vcodec_vpp1
>>>> +      - const: vcodec_apv
>>>> +
>>>> +  dma-coherent: true
>>>> +
>>>> +  firmware-name:
>>>> +    maxItems: 1
>>>> +
>>>> +  interconnects:
>>>> +    maxItems: 2
>>>> +
>>>> +  interconnect-names:
>>>> +    items:
>>>> +      - const: cpu-cfg
>>>> +      - const: video-mem
>>>> +
>>>> +  interrupts:
>>>> +    maxItems: 1
>>>> +
>>>> +  iommus:
>>>> +    minItems: 3
>>>> +    maxItems: 8
>>>
>>> I don't understand why this is flexible. Make it fixed size and anyway -
>>> list the items.
>>
>> kaanapali vpu generates 8 different stream-ids. Now, boards running kernel in
>> EL2 mode can list all of them, while boards running in EL1 can have only non
>> secure stream IDs. Min have the list of stream ids which can be enabled for all
>> type of boards, while max is for boards which can list all in HLOS given kernel
>> is in EL2 mode.
>>
>> Below crash would be seen if boards running kernel in EL1 mode lists the secure
>> ones.
> 
> 
> That has to be explained somewhere, e.g. comment, 

Sure, will add a description for iommus property explaining the same.

and still we need then
> EL2 DTS in the kernel. I did not see such so far, but maybe I missed it
> - can you link it?
> 

EL2 DTS for kaanapali is not yet posted to handle secure SIDs. While it is in
development, describing the secure stream-ids would ensure to cover all the
hardware generated IDs.

>>
>> [    1.361157] pc : qcom_smmu_write_s2cr+0x64/0xa4
>> [    1.361165] lr : arm_smmu_write_s2cr+0x2c/0xbc
>> [    1.361168] sp : ffff80008005b8f0
>> [    1.361169] x29: ffff80008005b8f0 x28: 0000000000000000 x27: ffffc7f252f45320
>> ....
>> [    1.361195] x2 : ffff800081200c48 x1 : 0000000000000048 x0 : ffff800081200000
>> [    1.361198] Call trace:
>> [    1.361199]  qcom_smmu_write_s2cr+0x64/0xa4 (P)
>> [    1.361203]  arm_smmu_master_install_s2crs+0x7c/0xac
>> [    1.361207]  arm_smmu_attach_dev+0xb0/0x1d4
>>
>> Could you please suggest on listing the iommu items ? I did not find the
>> relevant references in other bindings where flexible iommus is being listed.
> 
> 
> Just like every other list property - clocks, resets, power-domains.
> 
something like

iommu-names:
  items:
    - const: 0x1943
    - const: 0x1940
...

given that one of vpu sub hardware generates multiple SIDs, if we go with sub
hardware name in the list, the names would be repeated.

>>
>>>
>>> I already asked this.
>>>
>>>> +
>>>> +  memory-region:
>>>> +    minItems: 1
>>>> +    maxItems: 2
>>>
>>> Same comment. I already asked this about iommus.
>>
>> Same here, there aren't any bindings which lists for flexible memory-region.
>> Please suggest if there are any such references.
> 
> Because they do not matter for all other bindings, but it turned out
> recently it might matter for this device.

memory-region:
  minItems: 1
  maxItems: 2

memory-region-names:
  items:
    - const video_mem
    - const iris_resv

Regards,
Vikash

> 
> 
> Best regards,
> Krzysztof