Add 'max_num_buffers' field in vb2_queue struct to let drivers decide
how many buffers could be stored in a queue.
This require 'bufs' array to be allocated at queue init time and freed
when releasing the queue.
By default VB2_MAX_FRAME remains the limit.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
.../media/common/videobuf2/videobuf2-core.c | 46 +++++++++++++++----
.../media/common/videobuf2/videobuf2-v4l2.c | 6 +--
include/media/videobuf2-core.h | 12 ++++-
3 files changed, 52 insertions(+), 12 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index ce5b84b9bcd4..8c1df829745b 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -421,7 +421,7 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
*/
static void vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, unsigned int index)
{
- WARN_ON(index >= VB2_MAX_FRAME || q->bufs[index] || vb->vb2_queue);
+ WARN_ON(index >= q->max_num_buffers || q->bufs[index] || vb->vb2_queue);
q->bufs[index] = vb;
vb->index = index;
@@ -454,9 +454,12 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
struct vb2_buffer *vb;
int ret;
- /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
+ /*
+ * Ensure that the number of already queue + the number of buffers already
+ * in the queue is below q->max_num_buffers
+ */
num_buffers = min_t(unsigned int, num_buffers,
- VB2_MAX_FRAME - q_num_buffers);
+ q->max_num_buffers - q_num_buffers);
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
@@ -818,7 +821,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
unsigned int i;
- int ret;
+ int ret = 0;
if (q->streaming) {
dprintk(q, 1, "streaming active\n");
@@ -862,17 +865,22 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
/*
* Make sure the requested values and current defaults are sane.
*/
- WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
- num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
+ num_buffers = min_t(unsigned int, num_buffers, q->max_num_buffers);
memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
/*
* Set this now to ensure that drivers see the correct q->memory value
* in the queue_setup op.
*/
mutex_lock(&q->mmap_lock);
+ if (!q->bufs)
+ q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
+ if (!q->bufs)
+ ret = -ENOMEM;
q->memory = memory;
mutex_unlock(&q->mmap_lock);
+ if (ret)
+ return ret;
set_queue_coherency(q, non_coherent_mem);
/*
@@ -981,7 +989,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
bool no_previous_buffers = !q_num_bufs;
int ret = 0;
- if (q_num_bufs == VB2_MAX_FRAME) {
+ if (q->num_buffers == q->max_num_buffers) {
dprintk(q, 1, "maximum number of buffers already allocated\n");
return -ENOBUFS;
}
@@ -998,7 +1006,13 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
*/
mutex_lock(&q->mmap_lock);
q->memory = memory;
+ if (!q->bufs)
+ q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
+ if (!q->bufs)
+ ret = -ENOMEM;
mutex_unlock(&q->mmap_lock);
+ if (ret)
+ return ret;
q->waiting_for_buffers = !q->is_output;
set_queue_coherency(q, non_coherent_mem);
} else {
@@ -1010,7 +1024,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
return -EINVAL;
}
- num_buffers = min(*count, VB2_MAX_FRAME - q_num_bufs);
+ num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
if (requested_planes && requested_sizes) {
num_planes = requested_planes;
@@ -2470,6 +2484,16 @@ int vb2_core_queue_init(struct vb2_queue *q)
/*
* Sanity check
*/
+ /*
+ * For drivers who don't support max_num_buffers ensure
+ * a backward compatibility.
+ */
+ if (!q->max_num_buffers)
+ q->max_num_buffers = VB2_MAX_FRAME;
+
+ /* The maximum is limited by offset cookie encoding pattern */
+ q->max_num_buffers = min_t(unsigned int, q->max_num_buffers, MAX_BUFFER_INDEX);
+
if (WARN_ON(!q) ||
WARN_ON(!q->ops) ||
WARN_ON(!q->mem_ops) ||
@@ -2479,6 +2503,10 @@ int vb2_core_queue_init(struct vb2_queue *q)
WARN_ON(!q->ops->buf_queue))
return -EINVAL;
+ if (WARN_ON(q->max_num_buffers > MAX_BUFFER_INDEX) ||
+ WARN_ON(q->min_buffers_needed > q->max_num_buffers))
+ return -EINVAL;
+
if (WARN_ON(q->requires_requests && !q->supports_requests))
return -EINVAL;
@@ -2525,6 +2553,8 @@ void vb2_core_queue_release(struct vb2_queue *q)
__vb2_queue_cancel(q);
mutex_lock(&q->mmap_lock);
__vb2_queue_free(q, vb2_get_num_buffers(q));
+ kfree(q->bufs);
+ q->bufs = NULL;
mutex_unlock(&q->mmap_lock);
}
EXPORT_SYMBOL_GPL(vb2_core_queue_release);
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 9d3b828cc804..3d71c205406d 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -621,7 +621,7 @@ struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)
* This loop doesn't scale if there is a really large number of buffers.
* Maybe something more efficient will be needed in this case.
*/
- for (i = 0; i < vb2_get_num_buffers(q); i++) {
+ for (i = 0; i < q->max_num_buffers; i++) {
vb2 = vb2_get_buffer(q, i);
if (!vb2)
@@ -1136,7 +1136,7 @@ int _vb2_fop_release(struct file *file, struct mutex *lock)
if (lock)
mutex_lock(lock);
- if (file->private_data == vdev->queue->owner) {
+ if (!vdev->queue->owner || file->private_data == vdev->queue->owner) {
vb2_queue_release(vdev->queue);
vdev->queue->owner = NULL;
}
@@ -1264,7 +1264,7 @@ void vb2_video_unregister_device(struct video_device *vdev)
*/
get_device(&vdev->dev);
video_unregister_device(vdev);
- if (vdev->queue && vdev->queue->owner) {
+ if (vdev->queue) {
struct mutex *lock = vdev->queue->lock ?
vdev->queue->lock : vdev->lock;
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 8f9d9e4af5b1..5557d78b6f20 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -558,6 +558,9 @@ struct vb2_buf_ops {
* @dma_dir: DMA mapping direction.
* @bufs: videobuf2 buffer structures
* @num_buffers: number of allocated/used buffers
+ * @max_num_buffers: upper limit of number of allocated/used buffers.
+ * If set to 0 v4l2 core will change it VB2_MAX_FRAME
+ * for backward compatibility.
* @queued_list: list of buffers currently queued from userspace
* @queued_count: number of buffers queued and ready for streaming.
* @owned_by_drv_count: number of buffers owned by the driver
@@ -619,8 +622,9 @@ struct vb2_queue {
struct mutex mmap_lock;
unsigned int memory;
enum dma_data_direction dma_dir;
- struct vb2_buffer *bufs[VB2_MAX_FRAME];
+ struct vb2_buffer **bufs;
unsigned int num_buffers;
+ unsigned int max_num_buffers;
struct list_head queued_list;
unsigned int queued_count;
@@ -1248,6 +1252,12 @@ static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
unsigned int index)
{
+ if (!q->bufs)
+ return NULL;
+
+ if (index >= q->max_num_buffers)
+ return NULL;
+
if (index < q->num_buffers)
return q->bufs[index];
return NULL;
--
2.39.2
