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

[Krzysztof Kozlowski <krzk@kernel.org>]

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, 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?

> 
> [    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.

> 
>>
>> 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.


Best regards,
Krzysztof