Re: [PATCH v5 1/4] dt-bindings: media: qcom,venus-common: Add IOMMU IOVA reservation region

[Konrad Dybcio]

On 7/23/26 12:44 PM, Vikash Garodia wrote:
> 
> On 7/23/2026 2:36 PM, Konrad Dybcio wrote:
>> On 7/23/26 12:03 AM, Bryan O'Donoghue wrote:
>>> On 22/07/2026 14:41, Vikash Garodia wrote:
>>>> Update the memory-region property to support two regions:
>>>> 1. Firmware-loaded codec carveout (existing)
>>>> 2. IOMMU IOVA reservation region (new)
>>>>
>>>> The IOMMU IOVA reservation region is required to restrict usage of
>>>> specific IOVA memory range. For example, VPU restricts usage of 600MB
>>>> for specific streams, which could otherwise lead to device crash. This
>>>> change allows platforms to define separate memory regions for codec
>>>> carveout and IOVA restrictions.
>>>> This schema update supports existing DTS having single memory-region,
>>>> thereby allowing gradual migration of DTS to support two memory region.
>>>>
>>>> Signed-off-by: Vikash Garodia<vikash.garodia@xxxxxxxxxxxxxxxx>
>>>> ---
>>>
>>> I'm not mega-happy with this pattern being used - I prefer the pixel pixel_cb sub-node model you've proposed yourself.
>>>
>>> OTOH you're the maintainer so its really up to you how you want to arbitrate this - the 600MB constraint will work even if its not pretty or the best thing (tm).
>>>
>>> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
>>
>> Doesn't this cause the same limitation that the initial patch
>> by Daniel (all HW contexts can't access 0-600MiB anymore)?
> 
> Yes, it does, but for cases, like Shikra, which have single streams (with SMRs), there is no additional benefit in going with sub nodes in such case.

Please note that somewhere, I was under the impression all venus
impls suffer from that

Konrad