diff options
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 17 | ||||
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-core.c | 8 | ||||
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-v4l2.c | 2 | ||||
| -rw-r--r-- | include/uapi/linux/videodev2.h | 1 |
4 files changed, 19 insertions, 9 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst index d4bbbb0c60e8..e62a15782790 100644 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst @@ -59,9 +59,14 @@ When the I/O method is not supported the ioctl returns an ``EINVAL`` error code. Applications can call :ref:`VIDIOC_REQBUFS` again to change the number of -buffers, however this cannot succeed when any buffers are still mapped. -A ``count`` value of zero frees all buffers, after aborting or finishing -any DMA in progress, an implicit +buffers. Note that if any buffers are still mapped or exported via DMABUF, +then :ref:`VIDIOC_REQBUFS` can only succeed if the +``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` capability is set. Otherwise +:ref:`VIDIOC_REQBUFS` will return the ``EBUSY`` error code. +If ``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` is set, then these buffers are +orphaned and will be freed when they are unmapped or when the exported DMABUF +fds are closed. A ``count`` value of zero frees or orphans all buffers, after +aborting or finishing any DMA in progress, an implicit :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>`. @@ -112,6 +117,7 @@ any DMA in progress, an implicit .. _V4L2-BUF-CAP-SUPPORTS-USERPTR: .. _V4L2-BUF-CAP-SUPPORTS-DMABUF: .. _V4L2-BUF-CAP-SUPPORTS-REQUESTS: +.. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS: .. cssclass:: longtable @@ -132,6 +138,11 @@ any DMA in progress, an implicit * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS`` - 0x00000008 - This buffer type supports :ref:`requests <media-request-api>`. + * - ``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` + - 0x00000010 + - The kernel allows calling :ref:`VIDIOC_REQBUFS` while buffers are still + mapped or exported via DMABUF. These orphaned buffers will be freed + when they are unmapped or when the exported DMABUF fds are closed. Return Value ============ diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 03954c13024c..04d1250747cf 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -679,11 +679,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, * are not in use and can be freed. */ mutex_lock(&q->mmap_lock); - if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) { - mutex_unlock(&q->mmap_lock); - dprintk(1, "memory in use, cannot free\n"); - return -EBUSY; - } + if (debug && q->memory == VB2_MEMORY_MMAP && + __buffers_in_use(q)) + dprintk(1, "memory in use, orphaning buffers\n"); /* * Call queue_cancel to clean up any buffers in the diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index a17033ab2c22..f02d452ceeb9 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -624,7 +624,7 @@ EXPORT_SYMBOL(vb2_querybuf); static void fill_buf_caps(struct vb2_queue *q, u32 *caps) { - *caps = 0; + *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS; if (q->io_modes & VB2_MMAP) *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; if (q->io_modes & VB2_USERPTR) diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index c8e8ff810190..2a223835214c 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -879,6 +879,7 @@ struct v4l2_requestbuffers { #define V4L2_BUF_CAP_SUPPORTS_USERPTR (1 << 1) #define V4L2_BUF_CAP_SUPPORTS_DMABUF (1 << 2) #define V4L2_BUF_CAP_SUPPORTS_REQUESTS (1 << 3) +#define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS (1 << 4) /** * struct v4l2_plane - plane info for multi-planar buffers |