Just a small heads-up for an upcoming change...
On Tue October 2 2012 16:27:14 Tomasz Stanislawski wrote:
From: Sumit Semwal sumit.semwal@ti.com
This patch adds support for DMABUF memory type in videobuf2. It calls relevant APIs of dma_buf for v4l reqbuf / qbuf / dqbuf operations.
For this version, the support is for videobuf2 as a user of the shared buffer; so the allocation of the buffer is done outside of V4L2. [A sample allocator of dma-buf shared buffer is given at [1]]
[1]: Rob Clark's DRM: https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com [original work in the PoC for buffer sharing] Signed-off-by: Sumit Semwal sumit.semwal@ti.com Signed-off-by: Sumit Semwal sumit.semwal@linaro.org Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
drivers/media/video/Kconfig | 1 + drivers/media/video/videobuf2-core.c | 207 +++++++++++++++++++++++++++++++++- include/media/videobuf2-core.h | 27 +++++ 3 files changed, 232 insertions(+), 3 deletions(-)
<snip>
@@ -970,6 +1040,109 @@ static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b) } /**
- __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
- */
+static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b) +{
- struct v4l2_plane planes[VIDEO_MAX_PLANES];
- struct vb2_queue *q = vb->vb2_queue;
- void *mem_priv;
- unsigned int plane;
- int ret;
- int write = !V4L2_TYPE_IS_OUTPUT(q->type);
- /* Verify and copy relevant information provided by the userspace */
- ret = __fill_vb2_buffer(vb, b, planes);
Note that this code will have to change a bit when my multiplanar fixes go in:
http://www.spinics.net/lists/linux-media/msg54601.html
__fill_vb2_buffer is now a void function, so there won't be any need to check the error.
- if (ret)
return ret;- for (plane = 0; plane < vb->num_planes; ++plane) {
struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);if (IS_ERR_OR_NULL(dbuf)) {dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",plane);ret = -EINVAL;goto err;}/* use DMABUF size if length is not provided */if (planes[plane].length == 0)planes[plane].length = dbuf->size;if (planes[plane].length < planes[plane].data_offset +q->plane_sizes[plane]) {ret = -EINVAL;goto err;}/* Skip the plane if already verified */if (dbuf == vb->planes[plane].dbuf &&vb->v4l2_planes[plane].length == planes[plane].length) {dma_buf_put(dbuf);continue;}dprintk(1, "qbuf: buffer for plane %d changed\n", plane);/* Release previously acquired memory if present */__vb2_plane_dmabuf_put(q, &vb->planes[plane]);memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));/* Acquire each plane's memory */mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],dbuf, planes[plane].length, write);if (IS_ERR(mem_priv)) {dprintk(1, "qbuf: failed to attach dmabuf\n");ret = PTR_ERR(mem_priv);dma_buf_put(dbuf);goto err;}vb->planes[plane].dbuf = dbuf;vb->planes[plane].mem_priv = mem_priv;- }
- /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
* really we want to do this just before the DMA, not while queueing* the buffer(s)..*/- for (plane = 0; plane < vb->num_planes; ++plane) {
ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);if (ret) {dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",plane);goto err;}vb->planes[plane].dbuf_mapped = 1;- }
- /*
* Call driver-specific initialization on the newly acquired buffer,* if provided.*/- ret = call_qop(q, buf_init, vb);
- if (ret) {
dprintk(1, "qbuf: buffer initialization failed\n");goto err;- }
- /*
* Now that everything is in order, copy relevant information* provided by userspace.*/- for (plane = 0; plane < vb->num_planes; ++plane)
vb->v4l2_planes[plane] = planes[plane];- return 0;
+err:
- /* In case of errors, release planes that were already acquired */
- __vb2_buf_dmabuf_put(vb);
- return ret;
+}