On 08/10/18 12:46, Pavel Machek wrote:
> Hi!
>> From: Alexandre Courbot <acour...@chromium.org>
>>
>> Document the request API for V4L2 devices, and amend the documentation
>> of system calls influenced by it.
>>
>> Signed-off-by: Alexandre Courbot <acour...@chromium.org>
>> Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
>
>> --- a/Documentation/media/uapi/v4l/buffer.rst
>> +++ b/Documentation/media/uapi/v4l/buffer.rst
>> @@ -306,10 +306,15 @@ struct v4l2_buffer
>> - A place holder for future extensions. Drivers and applications
>> must set this to 0.
>> * - __u32
>> - - ``reserved``
>> + - ``request_fd``
>> -
>> - - A place holder for future extensions. Drivers and applications
>> - must set this to 0.
>> + - The file descriptor of the request to queue the buffer to. If
>> specified
>> + and flag ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will
>> be
>
> Delete "specified and" -- 0 is valid fd?
Good catch!
>
>> + queued to that request. This is set by the user when calling
>> + :ref:`ioctl VIDIOC_QBUF <VIDIOC_QBUF>` and ignored by other ioctls.
>> + If the device does not support requests, then ``EPERM`` will be
>> returned.
>> + If requests are supported but an invalid request FD is given, then
>> + ``ENOENT`` will be returned.
>
> Should this still specify that this should be 0 if
> V4L2_BUF_FLAG_REQUEST_FD is not set?
I don't think so. But I can mentioned with request_fd that it is ignored if
V4L2_BUF_FLAG_REQUEST_FD is not set.
Regards,
Hans
>
> Pavel
>
