On 02/10/2023 14:08, Benjamin Gaignard wrote:
> If V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS is set v4l2_create_buffers
Can you post a v4? This CAP name changed, so this is out of date.
Also, please put the videodev2.h change in a separate patch: that one
won't be merged since when this is merged we'll sync v4l-utils with
the latest kernel headers.
So this videodev2.h change is just for testing this.
Regards,
Hans
> max_buffers field reports the maximum number of buffers supported
> by the queue.
> Add a test to allocate this maximum value and make sure that one
> more allocation is failing.
> Display the flag in v4l2-ctl.>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> ---
> version 3:
> - change test fail check because vim2m do not allocate all the
> requested buffers (memory size limitation)
> include/linux/videodev2.h | 7 +++-
> utils/common/cv4l-helpers.h | 1 +
> utils/common/v4l-helpers.h | 5 +++
> utils/common/v4l2-info.cpp | 1 +
> utils/v4l2-compliance/v4l2-compliance.cpp | 1 +
> utils/v4l2-compliance/v4l2-compliance.h | 1 +
> utils/v4l2-compliance/v4l2-test-buffers.cpp | 42 ++++++++++++++++++++-
> 7 files changed, 56 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index c19441a1..ac5d2980 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -986,6 +986,7 @@ struct v4l2_requestbuffers {
> #define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS (1 << 4)
> #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 5)
> #define V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS (1 << 6)
> +#define V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS (1 << 7)
>
> /**
> * struct v4l2_plane - plane info for multi-planar buffers
> @@ -2531,6 +2532,9 @@ struct v4l2_dbg_chip_info {
> * @flags: additional buffer management attributes (ignored unless the
> * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability
> * and configured for MMAP streaming I/O).
> + * @max_buffers: if V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS capability flag is set
> + * this field indicate the maximum possible number of buffers
> + * for this queue.
> * @reserved: future extensions
> */
> struct v4l2_create_buffers {
> @@ -2540,7 +2544,8 @@ struct v4l2_create_buffers {
> struct v4l2_format format;
> __u32 capabilities;
> __u32 flags;
> - __u32 reserved[6];
> + __u32 max_buffers;
> + __u32 reserved[5];
> };
>
> /*
> diff --git a/utils/common/cv4l-helpers.h b/utils/common/cv4l-helpers.h
> index 91a04146..5a515a13 100644
> --- a/utils/common/cv4l-helpers.h
> +++ b/utils/common/cv4l-helpers.h
> @@ -743,6 +743,7 @@ public:
> unsigned g_type() const { return v4l_queue_g_type(this); }
> unsigned g_memory() const { return v4l_queue_g_memory(this); }
> unsigned g_buffers() const { return v4l_queue_g_buffers(this); }
> + unsigned g_max_buffers() const { return v4l_queue_g_max_buffers(this); }
> unsigned g_num_planes() const { return v4l_queue_g_num_planes(this); }
> unsigned g_capabilities() const { return v4l_queue_g_capabilities(this); }
> unsigned g_length(unsigned plane) const { return v4l_queue_g_length(this, plane); }
> diff --git a/utils/common/v4l-helpers.h b/utils/common/v4l-helpers.h
> index f8e96d58..5853f753 100644
> --- a/utils/common/v4l-helpers.h
> +++ b/utils/common/v4l-helpers.h
> @@ -1429,6 +1429,7 @@ struct v4l_queue {
> unsigned mappings;
> unsigned num_planes;
> unsigned capabilities;
> + unsigned max_buffers;
>
> __u32 lengths[VIDEO_MAX_PLANES];
> __u32 mem_offsets[VIDEO_MAX_FRAME][VIDEO_MAX_PLANES];
> @@ -1453,6 +1454,7 @@ static inline void v4l_queue_init(struct v4l_queue *q,
> static inline unsigned v4l_queue_g_type(const struct v4l_queue *q) { return q->type; }
> static inline unsigned v4l_queue_g_memory(const struct v4l_queue *q) { return q->memory; }
> static inline unsigned v4l_queue_g_buffers(const struct v4l_queue *q) { return q->buffers; }
> +static inline unsigned v4l_queue_g_max_buffers(const struct v4l_queue *q) { return q->max_buffers; }
> static inline unsigned v4l_queue_g_mappings(const struct v4l_queue *q) { return q->mappings; }
> static inline unsigned v4l_queue_g_num_planes(const struct v4l_queue *q) { return q->num_planes; }
> static inline unsigned v4l_queue_g_capabilities(const struct v4l_queue *q) { return q->capabilities; }
> @@ -1587,6 +1589,9 @@ static inline int v4l_queue_create_bufs(struct v4l_fd *f,
> if (ret)
> return ret;
> q->capabilities = createbufs.capabilities;
> + q->max_buffers = 32;
> + if (q->capabilities & V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS)
> + q->max_buffers = createbufs.max_buffers;
> q->buffers += createbufs.count;
> return v4l_queue_querybufs(f, q, q->buffers - createbufs.count);
> }
> diff --git a/utils/common/v4l2-info.cpp b/utils/common/v4l2-info.cpp
> index 4f8c2aa7..7adfedfc 100644
> --- a/utils/common/v4l2-info.cpp
> +++ b/utils/common/v4l2-info.cpp
> @@ -206,6 +206,7 @@ static constexpr flag_def bufcap_def[] = {
> { V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS, "orphaned-bufs" },
> { V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF, "m2m-hold-capture-buf" },
> { V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS, "mmap-cache-hints" },
> + { V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS, "set-max-bufs" },
> { 0, nullptr }
> };
>
> diff --git a/utils/v4l2-compliance/v4l2-compliance.cpp b/utils/v4l2-compliance/v4l2-compliance.cpp
> index f62016e5..56190448 100644
> --- a/utils/v4l2-compliance/v4l2-compliance.cpp
> +++ b/utils/v4l2-compliance/v4l2-compliance.cpp
> @@ -1448,6 +1448,7 @@ void testNode(struct node &node, struct node &node_m2m_cap, struct node &expbuf_
>
> printf("Buffer ioctls%s:\n", suffix);
> printf("\ttest VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: %s\n", ok(testReqBufs(&node)));
> + printf("\ttest CREATE_BUFS maximum buffers: %s\n", ok(testCreateBufsMax(&node)));
> // Reopen after each streaming test to reset the streaming state
> // in case of any errors in the preceeding test.
> node.reopen();
> diff --git a/utils/v4l2-compliance/v4l2-compliance.h b/utils/v4l2-compliance/v4l2-compliance.h
> index 7caf254b..4886e4c8 100644
> --- a/utils/v4l2-compliance/v4l2-compliance.h
> +++ b/utils/v4l2-compliance/v4l2-compliance.h
> @@ -383,6 +383,7 @@ int testReqBufs(struct node *node);
> int testReadWrite(struct node *node);
> int testExpBuf(struct node *node);
> int testBlockingWait(struct node *node);
> +int testCreateBufsMax(struct node *node);
>
> // 32-bit architecture, 32/64-bit time_t tests
> int testTime32_64(struct node *node);
> diff --git a/utils/v4l2-compliance/v4l2-test-buffers.cpp b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> index 6d592c9b..130c11fb 100644
> --- a/utils/v4l2-compliance/v4l2-test-buffers.cpp
> +++ b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> @@ -634,7 +634,6 @@ int testReqBufs(struct node *node)
> fail_on_test(testQueryBuf(node, i, q.g_buffers()));
> node->valid_memorytype |= 1 << V4L2_MEMORY_DMABUF;
> }
> -
> /*
> * It should be possible to set the same std, timings or
> * native size even after reqbufs was called.
> @@ -761,6 +760,47 @@ int testReqBufs(struct node *node)
> return 0;
> }
>
> +int testCreateBufsMax(struct node *node)
> +{
> + unsigned int i;
> + int ret;
> +
> + node->reopen();
> +
> + cv4l_queue q(0, 0);
> +
> + for (i = 1; i <= V4L2_BUF_TYPE_LAST; i++) {
> + if (!(node->valid_buftypes & (1 << i)))
> + continue;
> +
> + q.init(i, V4L2_MEMORY_USERPTR);
> + ret = q.create_bufs(node, 1);
> + if (!ret && (q.g_capabilities() & V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS)) {
> + fail_on_test(q.create_bufs(node, q.g_max_buffers() - q.g_buffers()));
> + ret = q.create_bufs(node, 1);
> + fail_on_test(ret != ENOBUFS && (q.g_max_buffers() == q.g_buffers()));
> + }
> +
> + q.init(i, V4L2_MEMORY_MMAP);
> + ret = q.create_bufs(node, 1);
> + if (!ret && (q.g_capabilities() & V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS)) {
> + fail_on_test(q.create_bufs(node, q.g_max_buffers() - q.g_buffers()));
> + ret = q.create_bufs(node, 1);
> + fail_on_test(ret != ENOBUFS && (q.g_max_buffers() == q.g_buffers()));
> + }
> +
> + q.init(i, V4L2_MEMORY_DMABUF);
> + ret = q.create_bufs(node, 1);
> + if (!ret && (q.g_capabilities() & V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS)) {
> + fail_on_test(q.create_bufs(node, q.g_max_buffers() - q.g_buffers()));
> + ret = q.create_bufs(node, 1);
> + fail_on_test(ret != ENOBUFS && (q.g_max_buffers() == q.g_buffers()));
> + }
> + }
> +
> + return 0;
> +}
> +
> int testExpBuf(struct node *node)
> {
> bool have_expbuf = false;
