Re: [REVIEW PATCH 10/11] vb2: set v4l2_buffer.bytesused to 0 for mp buffers

[Hans Verkuil <hverkuil@xs4all.nl>]

On 04/09/2014 07:21 PM, Sakari Ailus wrote:
> Hi Hans,
> 
> Thanks for the set.
> 
> On Mon, Mar 10, 2014 at 10:20:57PM +0100, Hans Verkuil wrote:
>> From: Hans Verkuil <hans.verkuil@cisco.com>
>>
>> The bytesused field of struct v4l2_buffer is not used for multiplanar
>> formats, so just zero it to prevent it from having some random value.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>> ---
>>  drivers/media/v4l2-core/videobuf2-core.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
>> index f68a60f..54a4150 100644
>> --- a/drivers/media/v4l2-core/videobuf2-core.c
>> +++ b/drivers/media/v4l2-core/videobuf2-core.c
>> @@ -583,6 +583,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
>>  		 * for it. The caller has already verified memory and size.
>>  		 */
>>  		b->length = vb->num_planes;
>> +		b->bytesused = 0;
> 
> I wonder if I'm missing something, but doesn't the value of the field come
> from the v4l2_buf field of the vb2_buffer which is allocated using kzalloc()
> in __vb2_queue_alloc(), and never changed afterwards?

You are right, this isn't necessary. I've dropped this patch.

Thanks!

	Hans

> 
>>  		memcpy(b->m.planes, vb->v4l2_planes,
>>  			b->length * sizeof(struct v4l2_plane));
>>  	} else {
>