Re: [PATCH v3 0/5] Introduce "non-pixel" sub node within iris video node

[neil.armstrong@linaro.org]

On 27/06/2025 17:48, Vikash Garodia wrote:
> This series introduces a sub node "non-pixel" within iris video node.
> Video driver registers this sub node as a platform device and configure
> it for DMA operations. All non pixel buffers, i.e bitstream, HFI queues
> and internal buffers related to bitstream processing, would be managed
> by this non_pixel device.
> 
> Purpose to add this sub-node:
> Iris device 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. For certain video usecase,
> this limited range in not sufficient enough, hence it brings the need to
> extend the possibility of higher IOVA range.
> 
> 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 into a separate platform device.
> With this, both iris and non-pixel device can have IOVA range of
> approximately 0-4GiB individually for each device, thereby doubling the
> range of addressable IOVA.
> 
> Tested on SM8550 and SA8775p hardwares.
> 
> Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
> ---
> Changes in v3:
> - Add info about change in iommus binding (Thanks Krzysztof)
> - Link to v2: https://lore.kernel.org/r/20250627-video_cb-v2-0-3931c3f49361@quicinc.com
> 
> Changes in v2:
> - Add ref to reserve-memory schema and drop it from redefining it in
> iris schema (Thanks Krzysztof)
> - Drop underscores and add info about non pixel buffers (Thanks Dmitry)
> - Link to v1: https://lore.kernel.org/r/20250620-video_cb-v1-0-9bcac1c8800c@quicinc.com
> 
> ---
> Vikash Garodia (5):
>        media: dt-bindings: add non-pixel property in iris schema
>        media: iris: register and configure non-pixel node as platform device
>        media: iris: use np_dev as preferred DMA device in HFI queue management
>        media: iris: select appropriate DMA device for internal buffers
>        media: iris: configure DMA device for vb2 queue on OUTPUT plane
> 
>   .../bindings/media/qcom,sm8550-iris.yaml           | 40 ++++++++++++++++-
>   drivers/media/platform/qcom/iris/iris_buffer.c     | 15 ++++++-
>   drivers/media/platform/qcom/iris/iris_core.h       |  2 +
>   drivers/media/platform/qcom/iris/iris_hfi_queue.c  | 20 ++++++---
>   drivers/media/platform/qcom/iris/iris_probe.c      | 50 +++++++++++++++++++++-
>   drivers/media/platform/qcom/iris/iris_vb2.c        |  4 ++
>   6 files changed, 119 insertions(+), 12 deletions(-)
> ---
> base-commit: 8d2b7fde56597ca912f5daaf3ab58915458ba1fc
> change-id: 20250619-video_cb-ea872d6e6627
> 
> Best regards,

I tried the patchset on SM8550 QRD and SM8650 QRD/HDK and the system just reboots
a few millisecond after probing iris, no error messages nor reboot to sahara mode.

The DT changeset for reference:
https://git.codelinaro.org/neil.armstrong/linux/-/commit/e1b3628469c038559a60d310386f006f353e3d59

Neil