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

[Krzysztof Kozlowski <krzk@kernel.org>]

On 01/07/2025 12:23, Vikash Garodia wrote:
> 
> On 6/30/2025 11:34 PM, neil.armstrong@linaro.org wrote:
>> 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
> 
> I was able to repro this case, the issue was due to a incorrect node name in
> driver. Fixing the name as per binding, fixes the issue for me. I have made the

Because this code was never tested... I found this response now, after I
briefly look at your code.


Best regards,
Krzysztof