When DELETE_BUFS will be introduced holes could created in bufs array.
To be able to reuse these unused indices reworking how create->index
is set is mandatory.
Let __vb2_queue_alloc() decide which first index is correct and
forward this to the caller.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
.../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
.../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
include/media/videobuf2-core.h | 5 ++++-
3 files changed, 31 insertions(+), 16 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index a183edf11586..cd2b9e51b9b0 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
*/
static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
unsigned int num_buffers, unsigned int num_planes,
- const unsigned plane_sizes[VB2_MAX_PLANES])
+ const unsigned int plane_sizes[VB2_MAX_PLANES],
+ unsigned int *first_index)
{
- unsigned int q_num_buffers = vb2_get_num_buffers(q);
unsigned int buffer, plane;
struct vb2_buffer *vb;
+ unsigned long index;
int ret;
/*
@@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
* in the queue is below q->max_num_buffers
*/
num_buffers = min_t(unsigned int, num_buffers,
- q->max_num_buffers - q_num_buffers);
+ q->max_num_buffers - vb2_get_num_buffers(q));
+
+ index = vb2_get_num_buffers(q);
+
+ *first_index = index;
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
@@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
vb->planes[plane].min_length = plane_sizes[plane];
}
- vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
+ vb2_queue_add_buffer(q, vb, index++);
call_void_bufop(q, init_buffer, vb);
/* Allocate video buffer memory for the MMAP type */
@@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int q_num_bufs = vb2_get_num_buffers(q);
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
- unsigned int i;
+ unsigned int i, first_index;
int ret = 0;
if (q->streaming) {
@@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
/* Finally, allocate buffers and video memory */
allocated_buffers =
- __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
+ __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
if (allocated_buffers == 0) {
dprintk(q, 1, "memory allocation failed\n");
ret = -ENOMEM;
@@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int flags, unsigned int *count,
unsigned int requested_planes,
- const unsigned int requested_sizes[])
+ const unsigned int requested_sizes[],
+ unsigned int *first_index)
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
@@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
/* Finally, allocate buffers and video memory */
allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
- num_planes, plane_sizes);
+ num_planes, plane_sizes, first_index);
if (allocated_buffers == 0) {
dprintk(q, 1, "memory allocation failed\n");
ret = -ENOMEM;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 54d572c3b515..3c0c423c5674 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
for (i = 0; i < requested_planes; i++)
if (requested_sizes[i] == 0)
return -EINVAL;
- return ret ? ret : vb2_core_create_bufs(q, create->memory,
- create->flags,
- &create->count,
- requested_planes,
- requested_sizes);
+ if (ret)
+ return ret;
+
+ ret = vb2_core_create_bufs(q, create->memory,
+ create->flags,
+ &create->count,
+ requested_planes,
+ requested_sizes,
+ &create->index);
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);
@@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
int res = vb2_verify_memory_type(vdev->queue, p->memory,
p->format.type);
- p->index = vdev->queue->num_buffers;
fill_buf_caps(vdev->queue, &p->capabilities);
validate_memory_flags(vdev->queue, p->memory, &p->flags);
/*
* If count == 0, then just check if memory and type are valid.
* Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
*/
- if (p->count == 0)
+ if (p->count == 0) {
+ p->index = vb2_get_num_buffers(vdev->queue);
return res != -EBUSY ? res : 0;
+ }
if (res)
return res;
if (vb2_queue_is_busy(vdev->queue, file))
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 7b84b4e2e273..607f2ba7a905 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
* @count: requested buffer count.
* @requested_planes: number of planes requested.
* @requested_sizes: array with the size of the planes.
+ * @first_index: index of the first created buffer, all allocated buffers have
+ * indices in the range [first..first+count]
*
* Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
* called internally by VB2 by an API-specific handler, like
@@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int flags, unsigned int *count,
unsigned int requested_planes,
- const unsigned int requested_sizes[]);
+ const unsigned int requested_sizes[],
+ unsigned int *first_index);
/**
* vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
--
2.40.1On 15/12/2023 10:08, Benjamin Gaignard wrote:
> When DELETE_BUFS will be introduced holes could created in bufs array.
> To be able to reuse these unused indices reworking how create->index
> is set is mandatory.
> Let __vb2_queue_alloc() decide which first index is correct and
> forward this to the caller.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
> include/media/videobuf2-core.h | 5 ++++-
> 3 files changed, 31 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index a183edf11586..cd2b9e51b9b0 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
> */
> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int num_buffers, unsigned int num_planes,
> - const unsigned plane_sizes[VB2_MAX_PLANES])
> + const unsigned int plane_sizes[VB2_MAX_PLANES],
> + unsigned int *first_index)
> {
> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
> unsigned int buffer, plane;
> struct vb2_buffer *vb;
> + unsigned long index;
> int ret;
>
> /*
> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> * in the queue is below q->max_num_buffers
> */
> num_buffers = min_t(unsigned int, num_buffers,
> - q->max_num_buffers - q_num_buffers);
> + q->max_num_buffers - vb2_get_num_buffers(q));
> +
> + index = vb2_get_num_buffers(q);
> +
> + *first_index = index;
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */
> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> vb->planes[plane].min_length = plane_sizes[plane];
> }
>
> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
> + vb2_queue_add_buffer(q, vb, index++);
> call_void_bufop(q, init_buffer, vb);
>
> /* Allocate video buffer memory for the MMAP type */
> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> - unsigned int i;
> + unsigned int i, first_index;
> int ret = 0;
>
> if (q->streaming) {
> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers =
> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
I'm thinking that after this 'if' it might be a good idea to add a:
/* There shouldn't be any buffers allocated, so first_index == 0 */
WARN_ON(first_index);
Just as a sanity check.
Regards,
Hans
> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[])
> + const unsigned int requested_sizes[],
> + unsigned int *first_index)
> {
> unsigned int num_planes = 0, num_buffers, allocated_buffers;
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
> - num_planes, plane_sizes);
> + num_planes, plane_sizes, first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 54d572c3b515..3c0c423c5674 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> for (i = 0; i < requested_planes; i++)
> if (requested_sizes[i] == 0)
> return -EINVAL;
> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
> - create->flags,
> - &create->count,
> - requested_planes,
> - requested_sizes);
> + if (ret)
> + return ret;
> +
> + ret = vb2_core_create_bufs(q, create->memory,
> + create->flags,
> + &create->count,
> + requested_planes,
> + requested_sizes,
> + &create->index);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>
> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
> int res = vb2_verify_memory_type(vdev->queue, p->memory,
> p->format.type);
>
> - p->index = vdev->queue->num_buffers;
> fill_buf_caps(vdev->queue, &p->capabilities);
> validate_memory_flags(vdev->queue, p->memory, &p->flags);
> /*
> * If count == 0, then just check if memory and type are valid.
> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
> */
> - if (p->count == 0)
> + if (p->count == 0) {
> + p->index = vb2_get_num_buffers(vdev->queue);
> return res != -EBUSY ? res : 0;
> + }
> if (res)
> return res;
> if (vb2_queue_is_busy(vdev->queue, file))
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 7b84b4e2e273..607f2ba7a905 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> * @count: requested buffer count.
> * @requested_planes: number of planes requested.
> * @requested_sizes: array with the size of the planes.
> + * @first_index: index of the first created buffer, all allocated buffers have
> + * indices in the range [first..first+count]
> *
> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
> * called internally by VB2 by an API-specific handler, like
> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[]);
> + const unsigned int requested_sizes[],
> + unsigned int *first_index);
>
> /**
> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
On 15/12/2023 10:08, Benjamin Gaignard wrote:
> When DELETE_BUFS will be introduced holes could created in bufs array.
> To be able to reuse these unused indices reworking how create->index
> is set is mandatory.
> Let __vb2_queue_alloc() decide which first index is correct and
> forward this to the caller.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
> include/media/videobuf2-core.h | 5 ++++-
> 3 files changed, 31 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index a183edf11586..cd2b9e51b9b0 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
> */
> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int num_buffers, unsigned int num_planes,
> - const unsigned plane_sizes[VB2_MAX_PLANES])
> + const unsigned int plane_sizes[VB2_MAX_PLANES],
> + unsigned int *first_index)
> {
> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
> unsigned int buffer, plane;
> struct vb2_buffer *vb;
> + unsigned long index;
> int ret;
>
> /*
> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> * in the queue is below q->max_num_buffers
> */
> num_buffers = min_t(unsigned int, num_buffers,
> - q->max_num_buffers - q_num_buffers);
> + q->max_num_buffers - vb2_get_num_buffers(q));
> +
> + index = vb2_get_num_buffers(q);
> +
> + *first_index = index;
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */
> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> vb->planes[plane].min_length = plane_sizes[plane];
> }
>
> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
> + vb2_queue_add_buffer(q, vb, index++);
> call_void_bufop(q, init_buffer, vb);
>
> /* Allocate video buffer memory for the MMAP type */
> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> - unsigned int i;
> + unsigned int i, first_index;
> int ret = 0;
>
> if (q->streaming) {
> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers =
> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[])
> + const unsigned int requested_sizes[],
> + unsigned int *first_index)
> {
> unsigned int num_planes = 0, num_buffers, allocated_buffers;
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
> - num_planes, plane_sizes);
> + num_planes, plane_sizes, first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 54d572c3b515..3c0c423c5674 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> for (i = 0; i < requested_planes; i++)
> if (requested_sizes[i] == 0)
> return -EINVAL;
> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
> - create->flags,
> - &create->count,
> - requested_planes,
> - requested_sizes);
> + if (ret)
> + return ret;
> +
> + ret = vb2_core_create_bufs(q, create->memory,
> + create->flags,
> + &create->count,
> + requested_planes,
> + requested_sizes,
> + &create->index);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>
> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
> int res = vb2_verify_memory_type(vdev->queue, p->memory,
> p->format.type);
>
> - p->index = vdev->queue->num_buffers;
> fill_buf_caps(vdev->queue, &p->capabilities);
> validate_memory_flags(vdev->queue, p->memory, &p->flags);
While reviewing this, I think I found a bug in the current code:
vb2_create_bufs() sets V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS, but
if p->count == 0, then that function isn't called...
> /*
> * If count == 0, then just check if memory and type are valid.
> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
> */
> - if (p->count == 0)
> + if (p->count == 0) {
> + p->index = vb2_get_num_buffers(vdev->queue);
> return res != -EBUSY ? res : 0;
...instead it just falls in this 'if'.
It would be better to refactor this so that vb2_ioctl_create_bufs()
relies on vb2_create_bufs for most of the work.
The reason for the messy code is that if p->count == 0, then it
should ignore any EBUSY results, since that should always work.
Alternatively, just copy the code from vb2_create_bufs here so the
flag is properly set.
In any case, fixing this is a separate patch that should go to v6.8.
Regards,
Hans
> + }
> if (res)
> return res;
> if (vb2_queue_is_busy(vdev->queue, file))
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 7b84b4e2e273..607f2ba7a905 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> * @count: requested buffer count.
> * @requested_planes: number of planes requested.
> * @requested_sizes: array with the size of the planes.
> + * @first_index: index of the first created buffer, all allocated buffers have
> + * indices in the range [first..first+count]
> *
> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
> * called internally by VB2 by an API-specific handler, like
> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[]);
> + const unsigned int requested_sizes[],
> + unsigned int *first_index);
>
> /**
> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
Le 15/01/2024 à 13:11, Hans Verkuil a écrit :
> On 15/12/2023 10:08, Benjamin Gaignard wrote:
>> When DELETE_BUFS will be introduced holes could created in bufs array.
>> To be able to reuse these unused indices reworking how create->index
>> is set is mandatory.
>> Let __vb2_queue_alloc() decide which first index is correct and
>> forward this to the caller.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>> ---
>> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
>> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
>> include/media/videobuf2-core.h | 5 ++++-
>> 3 files changed, 31 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index a183edf11586..cd2b9e51b9b0 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
>> */
>> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int num_buffers, unsigned int num_planes,
>> - const unsigned plane_sizes[VB2_MAX_PLANES])
>> + const unsigned int plane_sizes[VB2_MAX_PLANES],
>> + unsigned int *first_index)
>> {
>> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
>> unsigned int buffer, plane;
>> struct vb2_buffer *vb;
>> + unsigned long index;
>> int ret;
>>
>> /*
>> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> * in the queue is below q->max_num_buffers
>> */
>> num_buffers = min_t(unsigned int, num_buffers,
>> - q->max_num_buffers - q_num_buffers);
>> + q->max_num_buffers - vb2_get_num_buffers(q));
>> +
>> + index = vb2_get_num_buffers(q);
>> +
>> + *first_index = index;
>>
>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>> /* Allocate vb2 buffer structures */
>> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> vb->planes[plane].min_length = plane_sizes[plane];
>> }
>>
>> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
>> + vb2_queue_add_buffer(q, vb, index++);
>> call_void_bufop(q, init_buffer, vb);
>>
>> /* Allocate video buffer memory for the MMAP type */
>> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int q_num_bufs = vb2_get_num_buffers(q);
>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
>> - unsigned int i;
>> + unsigned int i, first_index;
>> int ret = 0;
>>
>> if (q->streaming) {
>> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>
>> /* Finally, allocate buffers and video memory */
>> allocated_buffers =
>> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
>> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
>> if (allocated_buffers == 0) {
>> dprintk(q, 1, "memory allocation failed\n");
>> ret = -ENOMEM;
>> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int flags, unsigned int *count,
>> unsigned int requested_planes,
>> - const unsigned int requested_sizes[])
>> + const unsigned int requested_sizes[],
>> + unsigned int *first_index)
>> {
>> unsigned int num_planes = 0, num_buffers, allocated_buffers;
>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>>
>> /* Finally, allocate buffers and video memory */
>> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
>> - num_planes, plane_sizes);
>> + num_planes, plane_sizes, first_index);
>> if (allocated_buffers == 0) {
>> dprintk(q, 1, "memory allocation failed\n");
>> ret = -ENOMEM;
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index 54d572c3b515..3c0c423c5674 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>> for (i = 0; i < requested_planes; i++)
>> if (requested_sizes[i] == 0)
>> return -EINVAL;
>> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
>> - create->flags,
>> - &create->count,
>> - requested_planes,
>> - requested_sizes);
>> + if (ret)
>> + return ret;
>> +
>> + ret = vb2_core_create_bufs(q, create->memory,
>> + create->flags,
>> + &create->count,
>> + requested_planes,
>> + requested_sizes,
>> + &create->index);
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>>
>> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
>> int res = vb2_verify_memory_type(vdev->queue, p->memory,
>> p->format.type);
>>
>> - p->index = vdev->queue->num_buffers;
>> fill_buf_caps(vdev->queue, &p->capabilities);
>> validate_memory_flags(vdev->queue, p->memory, &p->flags);
> While reviewing this, I think I found a bug in the current code:
>
> vb2_create_bufs() sets V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS, but
> if p->count == 0, then that function isn't called...
>
>> /*
>> * If count == 0, then just check if memory and type are valid.
>> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
>> */
>> - if (p->count == 0)
>> + if (p->count == 0) {
>> + p->index = vb2_get_num_buffers(vdev->queue);
>> return res != -EBUSY ? res : 0;
> ...instead it just falls in this 'if'.
>
> It would be better to refactor this so that vb2_ioctl_create_bufs()
> relies on vb2_create_bufs for most of the work.
>
> The reason for the messy code is that if p->count == 0, then it
> should ignore any EBUSY results, since that should always work.
>
> Alternatively, just copy the code from vb2_create_bufs here so the
> flag is properly set.
>
> In any case, fixing this is a separate patch that should go to v6.8.
Do you want this new patch to be in the next version of this series or completely
separated ?
Regards,
Benjamin
>
> Regards,
>
> Hans
>
>> + }
>> if (res)
>> return res;
>> if (vb2_queue_is_busy(vdev->queue, file))
>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
>> index 7b84b4e2e273..607f2ba7a905 100644
>> --- a/include/media/videobuf2-core.h
>> +++ b/include/media/videobuf2-core.h
>> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> * @count: requested buffer count.
>> * @requested_planes: number of planes requested.
>> * @requested_sizes: array with the size of the planes.
>> + * @first_index: index of the first created buffer, all allocated buffers have
>> + * indices in the range [first..first+count]
>> *
>> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
>> * called internally by VB2 by an API-specific handler, like
>> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int flags, unsigned int *count,
>> unsigned int requested_planes,
>> - const unsigned int requested_sizes[]);
>> + const unsigned int requested_sizes[],
>> + unsigned int *first_index);
>>
>> /**
>> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
On 15/01/2024 15:52, Benjamin Gaignard wrote:
>
> Le 15/01/2024 à 13:11, Hans Verkuil a écrit :
>> On 15/12/2023 10:08, Benjamin Gaignard wrote:
>>> When DELETE_BUFS will be introduced holes could created in bufs array.
>>> To be able to reuse these unused indices reworking how create->index
>>> is set is mandatory.
>>> Let __vb2_queue_alloc() decide which first index is correct and
>>> forward this to the caller.
>>>
>>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>>> ---
>>> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
>>> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
>>> include/media/videobuf2-core.h | 5 ++++-
>>> 3 files changed, 31 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>>> index a183edf11586..cd2b9e51b9b0 100644
>>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>>> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
>>> */
>>> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>> unsigned int num_buffers, unsigned int num_planes,
>>> - const unsigned plane_sizes[VB2_MAX_PLANES])
>>> + const unsigned int plane_sizes[VB2_MAX_PLANES],
>>> + unsigned int *first_index)
>>> {
>>> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
>>> unsigned int buffer, plane;
>>> struct vb2_buffer *vb;
>>> + unsigned long index;
>>> int ret;
>>> /*
>>> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>> * in the queue is below q->max_num_buffers
>>> */
>>> num_buffers = min_t(unsigned int, num_buffers,
>>> - q->max_num_buffers - q_num_buffers);
>>> + q->max_num_buffers - vb2_get_num_buffers(q));
>>> +
>>> + index = vb2_get_num_buffers(q);
>>> +
>>> + *first_index = index;
>>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>>> /* Allocate vb2 buffer structures */
>>> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>> vb->planes[plane].min_length = plane_sizes[plane];
>>> }
>>> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
>>> + vb2_queue_add_buffer(q, vb, index++);
>>> call_void_bufop(q, init_buffer, vb);
>>> /* Allocate video buffer memory for the MMAP type */
>>> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>> unsigned int q_num_bufs = vb2_get_num_buffers(q);
>>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>>> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
>>> - unsigned int i;
>>> + unsigned int i, first_index;
>>> int ret = 0;
>>> if (q->streaming) {
>>> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>> /* Finally, allocate buffers and video memory */
>>> allocated_buffers =
>>> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
>>> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
>>> if (allocated_buffers == 0) {
>>> dprintk(q, 1, "memory allocation failed\n");
>>> ret = -ENOMEM;
>>> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
>>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>>> unsigned int flags, unsigned int *count,
>>> unsigned int requested_planes,
>>> - const unsigned int requested_sizes[])
>>> + const unsigned int requested_sizes[],
>>> + unsigned int *first_index)
>>> {
>>> unsigned int num_planes = 0, num_buffers, allocated_buffers;
>>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>>> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>>> /* Finally, allocate buffers and video memory */
>>> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
>>> - num_planes, plane_sizes);
>>> + num_planes, plane_sizes, first_index);
>>> if (allocated_buffers == 0) {
>>> dprintk(q, 1, "memory allocation failed\n");
>>> ret = -ENOMEM;
>>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> index 54d572c3b515..3c0c423c5674 100644
>>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>>> for (i = 0; i < requested_planes; i++)
>>> if (requested_sizes[i] == 0)
>>> return -EINVAL;
>>> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
>>> - create->flags,
>>> - &create->count,
>>> - requested_planes,
>>> - requested_sizes);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = vb2_core_create_bufs(q, create->memory,
>>> + create->flags,
>>> + &create->count,
>>> + requested_planes,
>>> + requested_sizes,
>>> + &create->index);
>>> + return ret;
>>> }
>>> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>>> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
>>> int res = vb2_verify_memory_type(vdev->queue, p->memory,
>>> p->format.type);
>>> - p->index = vdev->queue->num_buffers;
>>> fill_buf_caps(vdev->queue, &p->capabilities);
>>> validate_memory_flags(vdev->queue, p->memory, &p->flags);
>> While reviewing this, I think I found a bug in the current code:
>>
>> vb2_create_bufs() sets V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS, but
>> if p->count == 0, then that function isn't called...
>>
>>> /*
>>> * If count == 0, then just check if memory and type are valid.
>>> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
>>> */
>>> - if (p->count == 0)
>>> + if (p->count == 0) {
>>> + p->index = vb2_get_num_buffers(vdev->queue);
>>> return res != -EBUSY ? res : 0;
>> ...instead it just falls in this 'if'.
>>
>> It would be better to refactor this so that vb2_ioctl_create_bufs()
>> relies on vb2_create_bufs for most of the work.
>>
>> The reason for the messy code is that if p->count == 0, then it
>> should ignore any EBUSY results, since that should always work.
>>
>> Alternatively, just copy the code from vb2_create_bufs here so the
>> flag is properly set.
>>
>> In any case, fixing this is a separate patch that should go to v6.8.
>
> Do you want this new patch to be in the next version of this series or completely
> separated ?
Completely separate. It's a fix that needs to go to v6.8.
Please prioritize this, once rc1 is released I'll prepare a PR with
several that need to go in v6.8.
Regards,
Hans
>
> Regards,
> Benjamin
>
>>
>> Regards,
>>
>> Hans
>>
>>> + }
>>> if (res)
>>> return res;
>>> if (vb2_queue_is_busy(vdev->queue, file))
>>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
>>> index 7b84b4e2e273..607f2ba7a905 100644
>>> --- a/include/media/videobuf2-core.h
>>> +++ b/include/media/videobuf2-core.h
>>> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>> * @count: requested buffer count.
>>> * @requested_planes: number of planes requested.
>>> * @requested_sizes: array with the size of the planes.
>>> + * @first_index: index of the first created buffer, all allocated buffers have
>>> + * indices in the range [first..first+count]
>>> *
>>> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
>>> * called internally by VB2 by an API-specific handler, like
>>> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>>> unsigned int flags, unsigned int *count,
>>> unsigned int requested_planes,
>>> - const unsigned int requested_sizes[]);
>>> + const unsigned int requested_sizes[],
>>> + unsigned int *first_index);
>>> /**
>>> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
On 15/12/2023 10:08, Benjamin Gaignard wrote:
> When DELETE_BUFS will be introduced holes could created in bufs array.
> To be able to reuse these unused indices reworking how create->index
> is set is mandatory.
> Let __vb2_queue_alloc() decide which first index is correct and
> forward this to the caller.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
> include/media/videobuf2-core.h | 5 ++++-
> 3 files changed, 31 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index a183edf11586..cd2b9e51b9b0 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
> */
You should update the comment before this function to explain what is
returned in first_index.
> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int num_buffers, unsigned int num_planes,
> - const unsigned plane_sizes[VB2_MAX_PLANES])
> + const unsigned int plane_sizes[VB2_MAX_PLANES],
> + unsigned int *first_index)
> {
> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
> unsigned int buffer, plane;
> struct vb2_buffer *vb;
> + unsigned long index;
> int ret;
>
> /*
> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> * in the queue is below q->max_num_buffers
> */
> num_buffers = min_t(unsigned int, num_buffers,
> - q->max_num_buffers - q_num_buffers);
> + q->max_num_buffers - vb2_get_num_buffers(q));
> +
> + index = vb2_get_num_buffers(q);
Perhaps move this line up, then you can use 'index' instead of
vb2_get_num_buffers() in the min_t line. Starting with the next
patch vb2_get_num_buffers becomes a more expensive operation.
General note: it is perhaps a good idea to check all the users of
vb2_get_num_buffers to make sure it is not called unnecessarily.
> +
> + *first_index = index;
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */
> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> vb->planes[plane].min_length = plane_sizes[plane];
> }
>
> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
> + vb2_queue_add_buffer(q, vb, index++);
> call_void_bufop(q, init_buffer, vb);
>
> /* Allocate video buffer memory for the MMAP type */
> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> - unsigned int i;
> + unsigned int i, first_index;
> int ret = 0;
>
> if (q->streaming) {
> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers =
> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[])
> + const unsigned int requested_sizes[],
> + unsigned int *first_index)
> {
> unsigned int num_planes = 0, num_buffers, allocated_buffers;
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>
> /* Finally, allocate buffers and video memory */
> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
> - num_planes, plane_sizes);
> + num_planes, plane_sizes, first_index);
> if (allocated_buffers == 0) {
> dprintk(q, 1, "memory allocation failed\n");
> ret = -ENOMEM;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 54d572c3b515..3c0c423c5674 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> for (i = 0; i < requested_planes; i++)
> if (requested_sizes[i] == 0)
> return -EINVAL;
> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
> - create->flags,
> - &create->count,
> - requested_planes,
> - requested_sizes);
> + if (ret)
> + return ret;
> +
> + ret = vb2_core_create_bufs(q, create->memory,
This can just be a direct 'return vb2_core_create_bufs(...'
> + create->flags,
> + &create->count,
> + requested_planes,
> + requested_sizes,
> + &create->index);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>
> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
> int res = vb2_verify_memory_type(vdev->queue, p->memory,
> p->format.type);
>
> - p->index = vdev->queue->num_buffers;
> fill_buf_caps(vdev->queue, &p->capabilities);
> validate_memory_flags(vdev->queue, p->memory, &p->flags);
> /*
> * If count == 0, then just check if memory and type are valid.
> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
> */
> - if (p->count == 0)
> + if (p->count == 0) {
> + p->index = vb2_get_num_buffers(vdev->queue);
> return res != -EBUSY ? res : 0;
> + }
> if (res)
> return res;
> if (vb2_queue_is_busy(vdev->queue, file))
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 7b84b4e2e273..607f2ba7a905 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> * @count: requested buffer count.
> * @requested_planes: number of planes requested.
> * @requested_sizes: array with the size of the planes.
> + * @first_index: index of the first created buffer, all allocated buffers have
> + * indices in the range [first..first+count]
> *
> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
> * called internally by VB2 by an API-specific handler, like
> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int flags, unsigned int *count,
> unsigned int requested_planes,
> - const unsigned int requested_sizes[]);
> + const unsigned int requested_sizes[],
> + unsigned int *first_index);
>
> /**
> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
Regards,
Hans
On 15/01/2024 12:00, Hans Verkuil wrote:
> On 15/12/2023 10:08, Benjamin Gaignard wrote:
>> When DELETE_BUFS will be introduced holes could created in bufs array.
>> To be able to reuse these unused indices reworking how create->index
>> is set is mandatory.
>> Let __vb2_queue_alloc() decide which first index is correct and
>> forward this to the caller.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>> ---
>> .../media/common/videobuf2/videobuf2-core.c | 22 ++++++++++++-------
>> .../media/common/videobuf2/videobuf2-v4l2.c | 20 +++++++++++------
>> include/media/videobuf2-core.h | 5 ++++-
>> 3 files changed, 31 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index a183edf11586..cd2b9e51b9b0 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -447,11 +447,12 @@ static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
>> */
>
> You should update the comment before this function to explain what is
> returned in first_index.
>
>> static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int num_buffers, unsigned int num_planes,
>> - const unsigned plane_sizes[VB2_MAX_PLANES])
>> + const unsigned int plane_sizes[VB2_MAX_PLANES],
>> + unsigned int *first_index)
>> {
>> - unsigned int q_num_buffers = vb2_get_num_buffers(q);
>> unsigned int buffer, plane;
>> struct vb2_buffer *vb;
>> + unsigned long index;
>> int ret;
>>
>> /*
>> @@ -459,7 +460,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> * in the queue is below q->max_num_buffers
>> */
>> num_buffers = min_t(unsigned int, num_buffers,
>> - q->max_num_buffers - q_num_buffers);
>> + q->max_num_buffers - vb2_get_num_buffers(q));
>> +
>> + index = vb2_get_num_buffers(q);
>
> Perhaps move this line up, then you can use 'index' instead of
> vb2_get_num_buffers() in the min_t line. Starting with the next
> patch vb2_get_num_buffers becomes a more expensive operation.
Never mind, this changes in the next patch.
That said, I would prefer to keep the q_num_buffers variable here and
use it in the min_t and index, and replace it in the next patch.
It is a bit confusing in this patch, it makes more sense in the next.
Regards,
Hans
>
> General note: it is perhaps a good idea to check all the users of
> vb2_get_num_buffers to make sure it is not called unnecessarily.>
>> +
>> + *first_index = index;
>>
>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>> /* Allocate vb2 buffer structures */
>> @@ -479,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> vb->planes[plane].min_length = plane_sizes[plane];
>> }
>>
>> - vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
>> + vb2_queue_add_buffer(q, vb, index++);
>> call_void_bufop(q, init_buffer, vb);
>>
>> /* Allocate video buffer memory for the MMAP type */
>> @@ -820,7 +825,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int q_num_bufs = vb2_get_num_buffers(q);
>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
>> - unsigned int i;
>> + unsigned int i, first_index;
>> int ret = 0;
>>
>> if (q->streaming) {
>> @@ -906,7 +911,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>>
>> /* Finally, allocate buffers and video memory */
>> allocated_buffers =
>> - __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
>> + __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes, &first_index);
>> if (allocated_buffers == 0) {
>> dprintk(q, 1, "memory allocation failed\n");
>> ret = -ENOMEM;
>> @@ -980,7 +985,8 @@ EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int flags, unsigned int *count,
>> unsigned int requested_planes,
>> - const unsigned int requested_sizes[])
>> + const unsigned int requested_sizes[],
>> + unsigned int *first_index)
>> {
>> unsigned int num_planes = 0, num_buffers, allocated_buffers;
>> unsigned plane_sizes[VB2_MAX_PLANES] = { };
>> @@ -1042,7 +1048,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>>
>> /* Finally, allocate buffers and video memory */
>> allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
>> - num_planes, plane_sizes);
>> + num_planes, plane_sizes, first_index);
>> if (allocated_buffers == 0) {
>> dprintk(q, 1, "memory allocation failed\n");
>> ret = -ENOMEM;
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index 54d572c3b515..3c0c423c5674 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -797,11 +797,16 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>> for (i = 0; i < requested_planes; i++)
>> if (requested_sizes[i] == 0)
>> return -EINVAL;
>> - return ret ? ret : vb2_core_create_bufs(q, create->memory,
>> - create->flags,
>> - &create->count,
>> - requested_planes,
>> - requested_sizes);
>> + if (ret)
>> + return ret;
>> +
>> + ret = vb2_core_create_bufs(q, create->memory,
>
> This can just be a direct 'return vb2_core_create_bufs(...'
>
>> + create->flags,
>> + &create->count,
>> + requested_planes,
>> + requested_sizes,
>> + &create->index);
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>>
>> @@ -1029,15 +1034,16 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
>> int res = vb2_verify_memory_type(vdev->queue, p->memory,
>> p->format.type);
>>
>> - p->index = vdev->queue->num_buffers;
>> fill_buf_caps(vdev->queue, &p->capabilities);
>> validate_memory_flags(vdev->queue, p->memory, &p->flags);
>> /*
>> * If count == 0, then just check if memory and type are valid.
>> * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
>> */
>> - if (p->count == 0)
>> + if (p->count == 0) {
>> + p->index = vb2_get_num_buffers(vdev->queue);
>> return res != -EBUSY ? res : 0;
>> + }
>> if (res)
>> return res;
>> if (vb2_queue_is_busy(vdev->queue, file))
>> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
>> index 7b84b4e2e273..607f2ba7a905 100644
>> --- a/include/media/videobuf2-core.h
>> +++ b/include/media/videobuf2-core.h
>> @@ -821,6 +821,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> * @count: requested buffer count.
>> * @requested_planes: number of planes requested.
>> * @requested_sizes: array with the size of the planes.
>> + * @first_index: index of the first created buffer, all allocated buffers have
>> + * indices in the range [first..first+count]
>> *
>> * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
>> * called internally by VB2 by an API-specific handler, like
>> @@ -837,7 +839,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
>> int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
>> unsigned int flags, unsigned int *count,
>> unsigned int requested_planes,
>> - const unsigned int requested_sizes[]);
>> + const unsigned int requested_sizes[],
>> + unsigned int *first_index);
>>
>> /**
>> * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
>
> Regards,
>
> Hans
>
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