[PATCH v7 12/49] media: videobuf2: Be more flexible on the number of queue stored buffers
Benjamin Gaignard
benjamin.gaignard at collabora.com
Thu Sep 14 06:32:46 PDT 2023
Add 'max_allowed_buffers' field in vb2_queue struct to let drivers decide
how many buffers could be stored in a queue.
This request '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 at collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
---
.../media/common/videobuf2/videobuf2-core.c | 40 ++++++++++++++-----
.../media/common/videobuf2/videobuf2-v4l2.c | 4 +-
include/media/videobuf2-core.h | 4 +-
3 files changed, 35 insertions(+), 13 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index afe76577acc1..ee4df7c68397 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -411,7 +411,7 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
*/
static bool vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, unsigned int index)
{
- if (index < VB2_MAX_FRAME && !q->bufs[index]) {
+ if (index < q->max_allowed_buffers && !q->bufs[index]) {
q->bufs[index] = vb;
vb->index = index;
vb->vb2_queue = q;
@@ -428,7 +428,7 @@ static bool vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, uns
*/
static void vb2_queue_remove_buffer(struct vb2_queue *q, struct vb2_buffer *vb)
{
- if (vb->index < VB2_MAX_FRAME) {
+ if (vb->index < q->max_allowed_buffers) {
q->bufs[vb->index] = NULL;
vb->vb2_queue = NULL;
}
@@ -449,9 +449,9 @@ 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 q->num_buffers+num_buffers is below q->max_allowed_buffers */
num_buffers = min_t(unsigned int, num_buffers,
- VB2_MAX_FRAME - q->num_buffers);
+ q->max_allowed_buffers - q->num_buffers);
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
@@ -814,7 +814,7 @@ 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");
@@ -858,17 +858,23 @@ 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);
+ WARN_ON(q->min_buffers_needed > q->max_allowed_buffers);
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_allowed_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_allowed_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);
/*
@@ -974,9 +980,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
bool no_previous_buffers = !q->num_buffers;
- int ret;
+ int ret = 0;
- if (q->num_buffers == VB2_MAX_FRAME) {
+ if (q->num_buffers == q->max_allowed_buffers) {
dprintk(q, 1, "maximum number of buffers already allocated\n");
return -ENOBUFS;
}
@@ -993,7 +999,13 @@ 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_allowed_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 {
@@ -1005,7 +1017,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
return -EINVAL;
}
- num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
+ num_buffers = min(*count, q->max_allowed_buffers - q->num_buffers);
if (requested_planes && requested_sizes) {
num_planes = requested_planes;
@@ -2515,6 +2527,12 @@ int vb2_core_queue_init(struct vb2_queue *q)
q->memory = VB2_MEMORY_UNKNOWN;
+ if (!q->max_allowed_buffers)
+ q->max_allowed_buffers = VB2_MAX_FRAME;
+
+ /* The maximum is limited by offset cookie encoding pattern */
+ q->max_allowed_buffers = min_t(unsigned int, q->max_allowed_buffers, BUFFER_INDEX_MASK + 1);
+
if (q->buf_struct_size == 0)
q->buf_struct_size = sizeof(struct vb2_buffer);
@@ -2539,6 +2557,8 @@ void vb2_core_queue_release(struct vb2_queue *q)
__vb2_queue_cancel(q);
mutex_lock(&q->mmap_lock);
__vb2_queue_free(q, q->num_buffers);
+ 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 f460cac560f6..87c2d5916960 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -1156,7 +1156,7 @@ 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;
}
@@ -1284,7 +1284,7 @@ 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 cd3ff1cd759d..97153c69583f 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -558,6 +558,7 @@ struct vb2_buf_ops {
* @dma_dir: DMA mapping direction.
* @bufs: videobuf2 buffer structures
* @num_buffers: number of allocated/used buffers
+ * @max_allowed_buffers: upper limit of number of allocated/used buffers
* @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 +620,9 @@ 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_allowed_buffers;
struct list_head queued_list;
unsigned int queued_count;
--
2.39.2
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