Re: [PATCH v3,04/21] v4l: add documentation for secure memory flag

From: Hans Verkuil
Date: Mon Jan 08 2024 - 03:29:59 EST


On 04/01/2024 21:05, Jeffrey Kardatzke wrote:
> On Mon, Dec 11, 2023 at 3:05 AM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
>>
>> On 06/12/2023 09:15, Yunfei Dong wrote:
>>> From: Jeffrey Kardatzke <jkardatzke@xxxxxxxxxx>
>>>
>>> Adds documentation for V4L2_MEMORY_FLAG_SECURE.
>>>
>>> Signed-off-by: Jeffrey Kardatzke <jkardatzke@xxxxxxxxxx>
>>> Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
>>> ---
>>> 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
>>>
>>