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@xxxxxxxxxxxxx> >> --- >> .../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 >