diff options
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 39 | ||||
| -rw-r--r-- | include/media/videobuf2-core.h | 2 |
2 files changed, 35 insertions, 6 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 8bc2a6e8623d..1329dccfa072 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -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; } diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index e49dc6b0de81..a5790fd5d125 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -337,6 +337,7 @@ struct v4l2_fh; * @io_modes: supported io methods (see vb2_io_modes enum) * @fileio_read_once: report EOF after reading the first buffer * @fileio_write_immediately: queue buffer after each write() call + * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver * @lock: pointer to a mutex that protects the vb2_queue struct. The * driver can set this to a mutex to let the v4l2 core serialize * the queuing ioctls. If the driver wants to handle locking @@ -388,6 +389,7 @@ struct vb2_queue { unsigned int io_modes; unsigned fileio_read_once:1; unsigned fileio_write_immediately:1; + unsigned allow_zero_bytesused:1; struct mutex *lock; struct v4l2_fh *owner; |