Re: [RFC PATCH v2 4/5] media: videobuf2: Define vb2_buf_type and vb2_memory

[Hans Verkuil <hverkuil@xs4all.nl>]

On 08/11/2015 04:19 AM, Junghak Sung wrote:
> 
> Hi Hans,
> 
> On 08/10/2015 05:22 PM, Hans Verkuil wrote:
>> On 07/31/2015 10:44 AM, Junghak Sung wrote:
>>> Define enum vb2_buf_type and enum vb2_memory for videobuf2-core. This
>>> change requires translation functions that could covert v4l2-core stuffs
>>> to videobuf2-core stuffs in videobuf2-v4l2.c file.
>>> The v4l2-specific member variables(e.g. type, memory) remains in
>>> struct vb2_queue for backward compatibility and performance of type translation.
>>>
>>> Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
>>> Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
>>> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
>>> Acked-by: Inki Dae <inki.dae@samsung.com>
>>> ---
>>>   drivers/media/v4l2-core/videobuf2-core.c |  139 +++++++++++---------
>>>   drivers/media/v4l2-core/videobuf2-v4l2.c |  209 ++++++++++++++++++++----------
>>>   include/media/videobuf2-core.h           |   99 +++++++++++---
>>>   include/media/videobuf2-v4l2.h           |   12 +-
>>>   4 files changed, 299 insertions(+), 160 deletions(-)
>>>
>>
>> <snip>
>>
>>> diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
>>> index 85527e9..22dd19c 100644
>>> --- a/drivers/media/v4l2-core/videobuf2-v4l2.c
>>> +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
>>> @@ -30,8 +30,46 @@
>>>   #include <media/v4l2-common.h>
>>>   #include <media/videobuf2-v4l2.h>
>>>
>>> +#define CREATE_TRACE_POINTS
>>>   #include <trace/events/v4l2.h>
>>>
>>> +static const enum vb2_buf_type _tbl_buf_type[] = {
>>> +	[V4L2_BUF_TYPE_VIDEO_CAPTURE]		= VB2_BUF_TYPE_VIDEO_CAPTURE,
>>> +	[V4L2_BUF_TYPE_VIDEO_OUTPUT]		= VB2_BUF_TYPE_VIDEO_OUTPUT,
>>> +	[V4L2_BUF_TYPE_VIDEO_OVERLAY]		= VB2_BUF_TYPE_VIDEO_OVERLAY,
>>> +	[V4L2_BUF_TYPE_VBI_CAPTURE]		= VB2_BUF_TYPE_VBI_CAPTURE,
>>> +	[V4L2_BUF_TYPE_VBI_OUTPUT]		= VB2_BUF_TYPE_VBI_OUTPUT,
>>> +	[V4L2_BUF_TYPE_SLICED_VBI_CAPTURE]	= VB2_BUF_TYPE_SLICED_VBI_CAPTURE,
>>> +	[V4L2_BUF_TYPE_SLICED_VBI_OUTPUT]	= VB2_BUF_TYPE_SLICED_VBI_OUTPUT,
>>> +	[V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY]	= VB2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY,
>>> +	[V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE]	= VB2_BUF_TYPE_VIDEO_CAPTURE_MPLANE,
>>> +	[V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE]	= VB2_BUF_TYPE_VIDEO_OUTPUT_MPLANE,
>>> +	[V4L2_BUF_TYPE_SDR_CAPTURE]		= VB2_BUF_TYPE_SDR_CAPTURE,
>>> +	[V4L2_BUF_TYPE_PRIVATE]			= VB2_BUF_TYPE_PRIVATE,
>>> +};
>>> +
>>> +static const enum vb2_memory _tbl_memory[] = {
>>> +	[V4L2_MEMORY_MMAP]	= VB2_MEMORY_MMAP,
>>> +	[V4L2_MEMORY_USERPTR]	= VB2_MEMORY_USERPTR,
>>> +	[V4L2_MEMORY_DMABUF]	= VB2_MEMORY_DMABUF,
>>> +};
>>> +
>>> +#define to_vb2_buf_type(type)					\
>>> +({								\
>>> +	enum vb2_buf_type ret = 0;				\
>>> +	if( type > 0 && type < ARRAY_SIZE(_tbl_buf_type) )	\
>>> +		ret = (_tbl_buf_type[type]);			\
>>> +	ret;							\
>>> +})
>>> +
>>> +#define to_vb2_memory(memory)					\
>>> +({								\
>>> +	enum vb2_memory ret = 0;				\
>>> +	if( memory > 0 && memory < ARRAY_SIZE(_tbl_memory) )	\
>>> +		ret = (_tbl_memory[memory]);			\
>>> +	ret;							\
>>> +})
>>> +
>>
>> <snip>
>>
>>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
>>> index dc405da..871fcc6 100644
>>> --- a/include/media/videobuf2-core.h
>>> +++ b/include/media/videobuf2-core.h
>>> @@ -15,9 +15,47 @@
>>>   #include <linux/mm_types.h>
>>>   #include <linux/mutex.h>
>>>   #include <linux/poll.h>
>>> -#include <linux/videodev2.h>
>>>   #include <linux/dma-buf.h>
>>>
>>> +#define VB2_MAX_FRAME               32
>>> +#define VB2_MAX_PLANES               8
>>> +
>>> +enum vb2_buf_type {
>>> +	VB2_BUF_TYPE_UNKNOWN			= 0,
>>> +	VB2_BUF_TYPE_VIDEO_CAPTURE		= 1,
>>> +	VB2_BUF_TYPE_VIDEO_OUTPUT		= 2,
>>> +	VB2_BUF_TYPE_VIDEO_OVERLAY		= 3,
>>> +	VB2_BUF_TYPE_VBI_CAPTURE		= 4,
>>> +	VB2_BUF_TYPE_VBI_OUTPUT			= 5,
>>> +	VB2_BUF_TYPE_SLICED_VBI_CAPTURE		= 6,
>>> +	VB2_BUF_TYPE_SLICED_VBI_OUTPUT		= 7,
>>> +	VB2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY	= 8,
>>> +	VB2_BUF_TYPE_VIDEO_CAPTURE_MPLANE	= 9,
>>> +	VB2_BUF_TYPE_VIDEO_OUTPUT_MPLANE	= 10,
>>> +	VB2_BUF_TYPE_SDR_CAPTURE		= 11,
>>> +	VB2_BUF_TYPE_DVB_CAPTURE		= 12,
>>> +	VB2_BUF_TYPE_PRIVATE			= 0x80,
>>> +};
>>> +
>>> +enum vb2_memory {
>>> +	VB2_MEMORY_UNKNOWN	= 0,
>>> +	VB2_MEMORY_MMAP		= 1,
>>> +	VB2_MEMORY_USERPTR	= 2,
>>> +	VB2_MEMORY_DMABUF	= 4,
>>> +};
>>> +
>>> +#define VB2_TYPE_IS_MULTIPLANAR(type)			\
>>> +	((type) == VB2_BUF_TYPE_VIDEO_CAPTURE_MPLANE	\
>>> +	 || (type) == VB2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>> +
>>> +#define VB2_TYPE_IS_OUTPUT(type)				\
>>> +	((type) == VB2_BUF_TYPE_VIDEO_OUTPUT			\
>>> +	 || (type) == VB2_BUF_TYPE_VIDEO_OUTPUT_MPLANE		\
>>> +	 || (type) == VB2_BUF_TYPE_VIDEO_OVERLAY		\
>>> +	 || (type) == VB2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY		\
>>> +	 || (type) == VB2_BUF_TYPE_VBI_OUTPUT			\
>>> +	 || (type) == VB2_BUF_TYPE_SLICED_VBI_OUTPUT)
>>
>> You don't actually need to create vb2_buf_type: unless I am mistaken, all that the
>> vb2 core needs to know is if it is a capture or output queue and possibly (not
>> sure about that) if it is single or multiplanar. So add fields to the vb2_queue struct
>> for that information and leave the buf_type to the v4l2 specific header and code.
>>
> Good idea. As your comment, the vb2_buf_type is used only for checking 
> if the buffer is a capture or output type in the videobuf2-core.c.
> But, I think it is better to add .is_output() to vb2_buf_ops in struct
> vb2_queue rather than add a fields.

Please just add a field. Callbacks are always harder to review and debug since you
have to lookup what the callbacks do.

It is much cleaner if you just add a field to the vb2 core for this.

Regards,

	Hans

> 
>> You also don't need the _tbl_memory[] array. All you need to do is to check in
>> videobuf2-v4l2.c that VB2_MEMORY* equals the V4L2_MEMORY_* defines and generate
>> a #error if not:
>>
>> #if VB2_MEMORY_MMAP != V4L2_MEMORY_MMAP || VB2_MEMORY_....
>> #error VB2_MEMORY_* != V4L2_MEMORY_*!
>> #endif
> 
> Good idea, too. For v3, I will rework as your guide.
> 
>>
>> Regards,
>>
>> 	Hans
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