[PATCH 55/55] media: videobuf2: core: Remove 'min_buffers_needed' field

From: Benjamin Gaignard
Date: Mon Nov 27 2023 - 11:59:46 EST


After clean up all the drivers it is possible to remove this
field from vb2_queue structure. It has been replace by
'min_dma_buffers_needed' which indicates how many buffers
a dma engine needs before start streaming and 'min_reqbufs_allocation'
to let drivers specify the minimum number of buffers to be
allocated when calling VIDIO_REQBUFS

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
.../media/common/videobuf2/videobuf2-core.c | 25 ++++++-------------
include/media/videobuf2-core.h | 5 ----
2 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index a6ec55db8635..223521cc135d 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -865,11 +865,10 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
/*
* Make sure the requested values and current defaults are sane.
*/
- num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
if (q->min_reqbufs_allocation)
- num_buffers = max_t(unsigned int, num_buffers, q->min_reqbufs_allocation);
+ num_buffers = max_t(unsigned int, *count, q->min_reqbufs_allocation);
else
- num_buffers = max_t(unsigned int, num_buffers, q->min_dma_buffers_needed + 1);
+ num_buffers = max_t(unsigned int, *count, q->min_dma_buffers_needed + 1);
min_reqbufs_needed = num_buffers;
num_buffers = min_t(unsigned int, num_buffers, q->max_num_buffers);
memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
@@ -1851,8 +1850,7 @@ int vb2_core_qbuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb,
* then we can finally call start_streaming().
*/
if (q->streaming && !q->start_streaming_called &&
- ((q->queued_count >= q->min_buffers_needed) ||
- (q->queued_count >= q->min_dma_buffers_needed))) {
+ q->queued_count >= q->min_dma_buffers_needed) {
ret = vb2_start_streaming(q);
if (ret) {
/*
@@ -2216,12 +2214,6 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
return -EINVAL;
}

- if (q_num_bufs < q->min_buffers_needed) {
- dprintk(q, 1, "need at least %u allocated buffers\n",
- q->min_buffers_needed);
- return -EINVAL;
- }
-
if (q_num_bufs < q->min_dma_buffers_needed) {
dprintk(q, 1, "need at least %u allocated buffers\n",
q->min_dma_buffers_needed);
@@ -2236,8 +2228,7 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
* Tell driver to start streaming provided sufficient buffers
* are available.
*/
- if (q->queued_count >= q->min_buffers_needed &&
- q->queued_count >= q->min_dma_buffers_needed) {
+ if (q->queued_count >= q->min_dma_buffers_needed) {
ret = vb2_start_streaming(q);
if (ret)
goto unprepare;
@@ -2517,8 +2508,7 @@ int vb2_core_queue_init(struct vb2_queue *q)
return -EINVAL;

if (WARN_ON(q->max_num_buffers > MAX_BUFFER_INDEX) ||
- WARN_ON(q->min_dma_buffers_needed > q->max_num_buffers) ||
- WARN_ON(q->min_buffers_needed > q->max_num_buffers))
+ WARN_ON(q->min_dma_buffers_needed > q->max_num_buffers))
return -EINVAL;

if (WARN_ON(q->requires_requests && !q->supports_requests))
@@ -2526,14 +2516,13 @@ int vb2_core_queue_init(struct vb2_queue *q)

/*
* This combination is not allowed since a non-zero value of
- * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
+ * q->min_dma_buffers_needed can cause vb2_core_qbuf() to fail if
* it has to call start_streaming(), and the Request API expects
* that queueing a request (and thus queueing a buffer contained
* in that request) will always succeed. There is no method of
* propagating an error back to userspace.
*/
- if (WARN_ON(q->supports_requests &&
- (q->min_buffers_needed || q->min_dma_buffers_needed)))
+ if (WARN_ON(q->supports_requests && q->min_dma_buffers_needed))
return -EINVAL;

INIT_LIST_HEAD(&q->queued_list);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 0bc97f28a7ea..353dccee7a30 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -546,10 +546,6 @@ struct vb2_buf_ops {
* @gfp_flags: additional gfp flags used when allocating the buffers.
* Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
* to force the buffer allocation to a specific memory zone.
- * @min_buffers_needed: the minimum number of buffers needed before
- * @start_streaming can be called. Used when a DMA engine
- * cannot be started unless at least this number of buffers
- * have been queued into the driver. (Deprecated)
* @min_dma_buffers_needed: the minimum number of buffers needed before
* @start_streaming can be called. Used when a DMA engine
* cannot be started unless at least this number of buffers
@@ -623,7 +619,6 @@ struct vb2_queue {
unsigned int buf_struct_size;
u32 timestamp_flags;
gfp_t gfp_flags;
- u32 min_buffers_needed;
u32 min_dma_buffers_needed;
u32 min_reqbufs_allocation;

--
2.39.2