lkml.org 
[lkml]   [2020]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC][PATCH 06/15] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT in CREATE_BUFS
From
Date
On 1/23/20 4:41 AM, Sergey Senozhatsky wrote:
> On (20/01/10 10:59), Hans Verkuil wrote:
> [..]
>>>
>>> num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
>>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> index 0eabb589684f..48d123a1ac2a 100644
>>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> @@ -730,6 +730,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>>> unsigned requested_sizes[VIDEO_MAX_PLANES];
>>> struct v4l2_format *f = &create->format;
>>> int ret = vb2_verify_memory_type(q, create->memory, f->type);
>>> + bool consistent = true;
>>> unsigned i;
>>>
>>> fill_buf_caps(q, &create->capabilities);
>>> @@ -775,7 +776,11 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>>> for (i = 0; i < requested_planes; i++)
>>> if (requested_sizes[i] == 0)
>>> return -EINVAL;
>>> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
>>> +
>>> + if (create->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
>>> + consistent = false;
>>> +
>>> + return ret ? ret : vb2_core_create_bufs(q, create->memory, consistent,
>>> &create->count, requested_planes, requested_sizes);
>>
>> As mentioned before: we need a V4L2_BUF_CAP capability.
>
> I can add V4L2_BUF_CAP for memory consistency. Isn't it just q->memory
> property though? User space may request MMAP consistent memory or MMAP
> inconsistent memory.

So instead of adding a flag we add a V4L2_MEMORY_MMAP_NON_CONSISTENT memory
type and add a V4L2_BUF_CAP_SUPPORTS_MMAP_NON_CONSISTENT to signal support
for this?

I like that better than a flag. It also automatically enforces that all
buffers must be of that type.

Regards,

Hans

>
> -ss
>

\
 
 \ /
  Last update: 2020-01-23 12:42    [W:0.082 / U:0.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site