On 05/07/2018 07:45 PM, Hyun Kwon wrote:
> Hi Hans,
>
> Thanks for the comment.
>
> On Mon, 2018-05-07 at 05:59:39 -0700, Hans Verkuil wrote:
>> Hi Satish,
>>
>> On 03/05/18 04:42, Satish Kumar Nagireddy wrote:
>>> The patches are for xilinx v4l. The patcheset enable support to handle
>>> multiplanar
>>> formats and 10 bit formats. Single planar implementation is removed as
>>> mplane can
>>> handle both.
>>
>> If I understand the format correctly, then the planes are contiguous in
>> memory,
>> i.e. it is a single buffer.
>>
>> You do not need to switch to the _MPLANE API for that: that API is meant for
>> the
>> case where the planes are not contiguous in memory but each plane has its own
>> buffer. And yes, we should have called it the _MBUFFER API or something :-(
>>
>> https://hverkuil.home.xs4all.nl/spec/uapi/v4l/pixfmt-nv12.html
>>
>> Switching to the _MPLANE API will actually break userspace, so that's another
>> reason why you shouldn't do this. But from what I can tell, it really isn't
>> needed at all.
>>
>
> Sharing some background to get your further input. :-)
>
> The Xilinx V4L driver is currently only for the soft IPs, which are
> programmable on FPGA, and those IPs are constantly updated. Initially, IPs
> didn't support _MPLANE formats, so it started with single buffer type format.
> Now, the IPs support _MPLANE formats, even though those formats are not part
> of
> this patch. Those formats are in downstream vendor tree and will be upstreamed
> at some point[1]. While implementing the multi-buffer formats, we had similar
> concern regarding UAPI and ended up having the module param[2]. It was there
> for a couple of Xilinx release cycles to migrate internal applications to
> _MPLANE formats and to get report if that breaks any external applications.
> Now
> we thought it's good time to hard-switch the driver to _MPLANE completely
> rather than keeping single buffer code, especially because it seems legal to
> support single buffer formats with _MPLANE type. If this is not the case and
> the applications with single buffer formats but without mplane formats should
> be supported, we can revive the single buffer code in one way or another.
In that case you need to split off the _MPLANE API change into a separate patch.
Switching to the MPLANE API has nothing to do with supporting this format, it is
done for a different reason (future support for real multiplane formats).
Since this also breaks userspace applications you will need to clearly state in
the commit log why this is a reasonable thing to do.
Regards,
Hans
>
> Thanks,
> -hyun
>
> [1]
> https://github.com/Xilinx/linux-xlnx/blob/xilinx-v2018.1/drivers/media/platform/xilinx/xilinx-vip.c#L33
> [2]
> https://github.com/Xilinx/linux-xlnx/blob/xilinx-v2018.1/drivers/media/platform/xilinx/xilinx-vipp.c#L40
>
>> Regards,
>>
>> Hans
>>
>>>
>>> Patch-set has downstream changes and bug fixes. Added new media bus format
>>> MEDIA_BUS_FMT_VYYUYY8_1X24, new pixel format V4L2_PIX_FMT_XV15 and rst
>>> documentation.
>>>
>>> Jeffrey Mouroux (1):
>>> uapi: media: New fourcc code and rst for 10 bit format
>>>
>>> Radhey Shyam Pandey (1):
>>> v4l: xilinx: dma: Remove colorspace check in xvip_dma_verify_format
>>>
>>> Rohit Athavale (1):
>>> xilinx: v4l: dma: Update driver to allow for probe defer
>>>
>>> Satish Kumar Nagireddy (4):
>>> media-bus: uapi: Add YCrCb 420 media bus format and rst
>>> v4l: xilinx: dma: Update video format descriptor
>>> v4l: xilinx: dma: Add multi-planar support
>>> v4l: xilinx: dma: Add support for 10 bit formats
>>>
>>> Vishal Sagar (1):
>>> xilinx: v4l: dma: Terminate DMA when media pipeline fail to start
>>>
>>> Documentation/media/uapi/v4l/pixfmt-xv15.rst | 134 +++++++++++++++++++
>>> Documentation/media/uapi/v4l/subdev-formats.rst | 38 +++++-
>>> Documentation/media/uapi/v4l/yuv-formats.rst | 1 +
>>> drivers/media/platform/xilinx/xilinx-dma.c | 170
>>> +++++++++++++++---------
>>> drivers/media/platform/xilinx/xilinx-dma.h | 4 +-
>>> drivers/media/platform/xilinx/xilinx-vip.c | 37 ++++--
>>> drivers/media/platform/xilinx/xilinx-vip.h | 15 ++-
>>> drivers/media/platform/xilinx/xilinx-vipp.c | 16 +--
>>> include/uapi/linux/media-bus-format.h | 3 +-
>>> include/uapi/linux/videodev2.h | 1 +
>>> 10 files changed, 333 insertions(+), 86 deletions(-)
>>> create mode 100644 Documentation/media/uapi/v4l/pixfmt-xv15.rst
>>>
>>
