If V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS is set v4l2_create_buffers
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>
---
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 | 39 ++++++++++++++++++++-
7 files changed, 53 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..b595d1d1 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 +760,44 @@ 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()));
+ fail_on_test(q.create_bufs(node, 1) != ENOBUFS);
+ }
+
+ 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()));
+ fail_on_test(q.create_bufs(node, 1) != ENOBUFS);
+ }
+
+ 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()));
+ fail_on_test(q.create_bufs(node, 1) != ENOBUFS);
+ }
+ }
+
+ return 0;
+}
+
int testExpBuf(struct node *node)
{
bool have_expbuf = false;
--
2.39.2
