From: Hans Verkuil <hverkuil@xs4all.nl>
To: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hans Verkuil <hans.verkuil@cisco.com>,
Tomasz Figa <tfiga@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Kyungmin Park <kyungmin.park@samsung.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Sakari Ailus <sakari.ailus@iki.fi>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Pawel Osciak <posciak@chromium.org>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 05/11] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag
Date: Fri, 28 Feb 2020 09:49:45 +0100 [thread overview]
Message-ID: <5c397f03-ffcf-6686-aa43-393771533cae@xs4all.nl> (raw)
In-Reply-To: <20200228013820.GM122464@google.com>
On 2/28/20 2:38 AM, Sergey Senozhatsky wrote:
> On (20/02/27 13:36), Hans Verkuil wrote:
>>> diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
>>> index bd08e4f77ae4..6a8a4d5de2f1 100644
>>> --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
>>> +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
>>> @@ -121,7 +121,13 @@ than the number requested.
>>> other changes, then set ``count`` to 0, ``memory`` to
>>> ``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
>>> * - __u32
>>> - - ``reserved``\ [7]
>>> + - ``flags``
>>> + - Specifies additional buffer management attributes.
>>> + See :ref:`memory-flags`. Old drivers and applications must set it to
>>> + zero.
>>
>> Drop the last sentence, it's not relevant.
>
> OK.
>
>>> +
>>> + * - __u32
>>> + - ``reserved``\ [6]
>>> - A place holder for future extensions. Drivers and applications
>>> must set the array to zero.
>>
>> Old drivers and applications still think reserved is [7] and will zero this.
>
> OK.
>
> Hmm... If those apps use hard-coded size then we might have a problem.
> If they use sizeof(reserved) then everything is OK. Shall we also have
> a union here?
No, apps will use sizeof(reserved).
Regards,
Hans
>
>>> diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
>>> index 917df6fb6486..e52cc4401fba 100644
>>> --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
>>> +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
>>> @@ -112,10 +112,19 @@ aborting or finishing any DMA in progress, an implicit
>>> ``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
>>> free any previously allocated buffers, so this is typically something
>>> that will be done at the start of the application.
>>> - * - __u32
>>> + * - union
>>> + - (anonymous)
>>
>> Anonymous unions are formatted a bit differently (I made a very recent patch
>> that unified the union formatting in the v4l docs). See e.g.
>> Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst.
>
> OK, will take a look.
>
> -ss
>
next prev parent reply other threads:[~2020-02-28 8:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 11:15 [PATCHv3 00/11] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 01/11] videobuf2: add cache management members Sergey Senozhatsky
2020-02-27 11:55 ` Hans Verkuil
2020-02-28 1:25 ` Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 02/11] videobuf2: handle V4L2 buffer cache flags Sergey Senozhatsky
2020-02-27 11:58 ` Hans Verkuil
2020-02-28 1:20 ` Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 03/11] videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-02-27 12:25 ` Hans Verkuil
2020-02-28 1:39 ` Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 04/11] videobuf2: add queue memory consistency parameter Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 05/11] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-02-27 12:36 ` Hans Verkuil
2020-02-28 1:38 ` Sergey Senozhatsky
2020-02-28 8:49 ` Hans Verkuil [this message]
2020-02-28 3:57 ` Sergey Senozhatsky
2020-02-28 8:50 ` Hans Verkuil
2020-02-28 11:39 ` Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 06/11] videobuf2: factor out planes prepare/finish functions Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 07/11] videobuf2: do not sync caches when we are allowed not to Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 08/11] videobuf2: check ->synced flag in prepare() and finish() Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 09/11] videobuf2: add begin/end cpu_access callbacks to dma-contig Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 10/11] videobuf2: add begin/end cpu_access callbacks to dma-sg Sergey Senozhatsky
2020-02-26 11:15 ` [PATCHv3 11/11] videobuf2: don't test db_attach in dma-contig prepare and finish Sergey Senozhatsky
2020-02-27 12:39 ` [PATCHv3 00/11] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Hans Verkuil
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