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

Vikash Garodia
2025-07-01T10:23:43Z

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
comment in your code branch [1], which should fix it for you as well. Please
share your observations.

Regards,
Vikash

[1]
https://git.codelinaro.org/neil.armstrong/linux/-/commit/e1b3628469c038559a60d310386f006f353e3d59#note_23930047

>
> Neil