diff options
Diffstat (limited to 'include/media/videobuf2-core.h')
| -rw-r--r-- | include/media/videobuf2-core.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 667bf9ee1101..4a8b9135cec8 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -549,9 +549,21 @@ struct vb2_buf_ops { * @start_streaming can be called. Used when a DMA engine * cannot be started unless at least this number of buffers * have been queued into the driver. - * VIDIOC_REQBUFS will ensure at least @min_queued_buffers + * VIDIOC_REQBUFS will ensure at least @min_queued_buffers + 1 * buffers will be allocated. Note that VIDIOC_CREATE_BUFS will not * modify the requested buffer count. + * @min_reqbufs_allocation: the minimum number of buffers to be allocated when + * calling VIDIOC_REQBUFS. Note that VIDIOC_CREATE_BUFS will *not* + * modify the requested buffer count and does not use this field. + * Drivers can set this if there has to be a certain number of + * buffers available for the hardware to work effectively. + * This allows calling VIDIOC_REQBUFS with a buffer count of 1 and + * it will be automatically adjusted to a workable buffer count. + * If set, then @min_reqbufs_allocation must be larger than + * @min_queued_buffers + 1. + * If this field is > 3, then it is highly recommended that the + * driver implements the V4L2_CID_MIN_BUFFERS_FOR_CAPTURE/OUTPUT + * control. * @alloc_devs: &struct device memory type/allocator-specific per-plane device */ /* @@ -622,6 +634,7 @@ struct vb2_queue { u32 timestamp_flags; gfp_t gfp_flags; u32 min_queued_buffers; + u32 min_reqbufs_allocation; struct device *alloc_devs[VB2_MAX_PLANES]; |