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Date: Mon, 8 Jan 2024 09:29:42 +0100
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Subject: Re: [PATCH v3,04/21] v4l: add documentation for secure memory flag
To: Jeffrey Kardatzke <jkardatzke@google.com>
Cc: Yunfei Dong <yunfei.dong@mediatek.com>,
 =?UTF-8?Q?N=C3=ADcolas_F_=2E_R_=2E_A_=2E_Prado?= <nfraprado@collabora.com>,
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 Yong Wu <yong.wu@mediatek.com>, Hsin-Yi Wang <hsinyi@chromium.org>,
 Fritz Koenig <frkoenig@chromium.org>, Daniel Vetter <daniel@ffwll.ch>,
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References: <20231206081538.17056-1-yunfei.dong@mediatek.com>
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From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
In-Reply-To: <CA+ddPcM6nz0ufF5NXUq7E_vF6HnFKrEEag5iUDAknT6=hWTCNQ@mail.gmail.com>
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On 04/01/2024 21:05, Jeffrey Kardatzke wrote:
> On Mon, Dec 11, 2023 at 3:05 AM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote:
>>
>> On 06/12/2023 09:15, Yunfei Dong wrote:
>>> From: Jeffrey Kardatzke <jkardatzke@google.com>
>>>
>>> Adds documentation for V4L2_MEMORY_FLAG_SECURE.
>>>
>>> Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
>>> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
>>> ---
>>>  Documentation/userspace-api/media/v4l/buffer.rst | 8 +++++++-
>>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
>>> index 52bbee81c080..a5a7d1c72d53 100644
>>> --- a/Documentation/userspace-api/media/v4l/buffer.rst
>>> +++ b/Documentation/userspace-api/media/v4l/buffer.rst
>>> @@ -696,7 +696,7 @@ enum v4l2_memory
>>>
>>>  .. _memory-flags:
>>>
>>> -Memory Consistency Flags
>>> +Memory Flags
>>>  ------------------------
>>>
>>>  .. raw:: latex
>>> @@ -728,6 +728,12 @@ Memory Consistency Flags
>>>       only if the buffer is used for :ref:`memory mapping <mmap>` I/O and the
>>>       queue reports the :ref:`V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS
>>>       <V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS>` capability.
>>> +    * .. _`V4L2-MEMORY-FLAG-SECURE`:
>>> +
>>> +      - ``V4L2_MEMORY_FLAG_SECURE``
>>> +      - 0x00000002
>>> +      - DMA bufs passed into the queue will be validated to ensure they were
>>> +     allocated from a secure dma-heap.
>>
>> Hmm, that needs a bit more work. How about:
>>
>> - The queued buffers are expected to be in secure memory. If not, an error will be
>>   returned. This flag can only be used with ``V4L2_MEMORY_DMABUF``. Typically
>>   secure buffers are allocated using a secure dma-heap. This flag can only be
>>   specified if the ``V4L2_BUF_CAP_SUPPORTS_SECURE_MEM`` is set.
>>
> 
> Thanks Hans. Yunfei, can you integrate this change into the patch please?
> 
>> In addition, the title of this table is currently "Memory Consistency Flags": that
>> should be renamed to "Memory Flags".
> 
> Hans, the patch is already renaming the table as you suggested. :)
> (unless there's some other spot I'm missing)

Sorry for the noise, I missed that change.

Regards,

	Hans

>>
>> Regards,
>>
>>         Hans
>>
>>>
>>>  .. raw:: latex
>>>
>>