Re: [PATCH 1/5] dt-bindings: media: qcom,sm8550-iris: add non_pixel and resv_region properties
From: Krzysztof Kozlowski
Date: Fri Jun 20 2025 - 02:42:11 EST
On 20/06/2025 08:20, Vikash Garodia wrote:
> Existing definition limits the IOVA to an addressable range of 4GiB, and
> even within that range, some of the space is used by IO registers,
> thereby limiting the available IOVA to even lesser. Video hardware is
> designed to emit different stream-ID for pixel and non_pixel buffers,
> thereby introduce a non_pixel sub node to handle non_pixel stream-ID.
>
> With this, both iris and non_pixel device can have IOVA range of 0-4GiB
> individually. Certain video usecases like higher video concurrency needs
> IOVA higher than 4GiB.
>
> Add the "resv_region" property, which defines reserved IOVA regions that
> are *excluded* from addressable range. Video hardware generates
> different stream IDs based on the range of IOVA addresses. Thereby IOVA
> addresses for firmware and data buffers need to be non overlapping. For
> ex. 0x0-0x25800000 address range is reserved for firmware stream-ID,
> while non_pixel (bitstream ) stream-ID can be generated by hardware only
> when bitstream buffers IOVA address is from 0x25800000-0xe0000000.
>
Also, use correct subject prefixes.
Best regards,
Krzysztof