[media] vb2: add allow_zero_bytesused flag to the vb2_queue struct

The vb2: fix bytesused == 0 handling (8a75ffb) patch changed the behavior
of __fill_vb2_buffer function, so that if bytesused is 0 it is set to the
size of the buffer. However, bytesused set to 0 is used by older codec
drivers as as indication used to mark the end of stream.

To keep backward compatibility, this patch adds a flag passed to the
vb2_queue_init function - allow_zero_bytesused. If the flag is set upon
initialization of the queue, the videobuf2 keeps the value of bytesused
intact in the OUTPUT queue and passes it to the driver.

Reported-by: Nicolas Dufresne <[email protected]>
Signed-off-by: Kamil Debski <[email protected]>
Acked-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
This commit is contained in:
Kamil Debski 2015-02-23 09:26:17 -03:00 • committed by Mauro Carvalho Chehab
commit f61bf13b6a
2 changed files with 35 additions and 6 deletions

View file

@ -1247,6 +1247,16 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
{
unsigned int plane;
if (V4L2_TYPE_IS_OUTPUT(b->type)) {
if (WARN_ON_ONCE(b->bytesused == 0)) {
pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
if (vb->vb2_queue->allow_zero_bytesused)
pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
else
pr_warn_once("use the actual size instead.\n");
}
}
if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
if (b->memory == V4L2_MEMORY_USERPTR) {
for (plane = 0; plane < vb->num_planes; ++plane) {
@ -1276,13 +1286,22 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
* userspace clearly never bothered to set it and
* it's a safe assumption that they really meant to
* use the full plane sizes.
*
* Some drivers, e.g. old codec drivers, use bytesused == 0
* as a way to indicate that streaming is finished.
* In that case, the driver should use the
* allow_zero_bytesused flag to keep old userspace
* applications working.
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
struct v4l2_plane *pdst = &v4l2_planes[plane];
struct v4l2_plane *psrc = &b->m.planes[plane];
pdst->bytesused = psrc->bytesused ?
psrc->bytesused : pdst->length;
if (vb->vb2_queue->allow_zero_bytesused)
pdst->bytesused = psrc->bytesused;
else
pdst->bytesused = psrc->bytesused ?
psrc->bytesused : pdst->length;
pdst->data_offset = psrc->data_offset;
}
}
@ -1295,6 +1314,11 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
*
* If bytesused == 0 for the output buffer, then fall back
* to the full buffer size as that's a sensible default.
*
* Some drivers, e.g. old codec drivers, use bytesused == 0 as
* a way to indicate that streaming is finished. In that case,
* the driver should use the allow_zero_bytesused flag to keep
* old userspace applications working.
*/
if (b->memory == V4L2_MEMORY_USERPTR) {
v4l2_planes[0].m.userptr = b->m.userptr;
@ -1306,10 +1330,13 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
v4l2_planes[0].length = b->length;
}
if (V4L2_TYPE_IS_OUTPUT(b->type))
v4l2_planes[0].bytesused = b->bytesused ?
b->bytesused : v4l2_planes[0].length;
else
if (V4L2_TYPE_IS_OUTPUT(b->type)) {
if (vb->vb2_queue->allow_zero_bytesused)
v4l2_planes[0].bytesused = b->bytesused;
else
v4l2_planes[0].bytesused = b->bytesused ?
b->bytesused : v4l2_planes[0].length;
} else
v4l2_planes[0].bytesused = 0;
}