Commit c838530d authored by Benjamin Gaignard's avatar Benjamin Gaignard Committed by Mauro Carvalho Chehab
Browse files

media: media videobuf2: Be more flexible on the number of queue stored buffers 



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: default avatarBenjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 4545ca51

drivers/media/common/videobuf2/videobuf2-core.c

+38 −8
Original line number Diff line number Diff line
@@ -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);

drivers/media/common/videobuf2/videobuf2-v4l2.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

include/media/videobuf2-core.h

+11 −1
Original line number Diff line number Diff line
@@ -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;