2024-02-06 08:55:22

by Benjamin Gaignard

[permalink] [raw]
Subject: [PATCH v19.1 1/9] media: videobuf2: Update vb2_is_busy() logic

Do not rely on the number of allocated buffers to know if the
queue is busy but on a flag set when at least one buffer has been allocated
by REQBUFS or CREATE_BUFS ioctl.
The flag is reset when REQBUFS is called with count = 0 or the file
handle is closed.
This is needed because delete buffers feature will be able to remove
all the buffers from a queue while streaming so relying on the number
of allocated buffers in the queue won't be possible.

Signed-off-by: Benjamin Gaignard <[email protected]>
---
version 19.1:
- Add q->is_busy = 0 in vb2_core_queue_release()
- Fix q->is_busy usage in vb2_core_reqbufs()
- Reword commit message.
- Fix typo in commit message

drivers/media/common/videobuf2/videobuf2-core.c | 4 ++++
include/media/videobuf2-core.h | 4 +++-
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index b6bf8f232f48..d8b3c04cb3b5 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -854,6 +854,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
__vb2_queue_free(q, q_num_bufs);
mutex_unlock(&q->mmap_lock);

+ q->is_busy = 0;
/*
* In case of REQBUFS(0) return immediately without calling
* driver's queue_setup() callback and allocating resources.
@@ -966,6 +967,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
*/
*count = allocated_buffers;
q->waiting_for_buffers = !q->is_output;
+ q->is_busy = 1;

return 0;

@@ -1091,6 +1093,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
* to the userspace.
*/
*count = allocated_buffers;
+ q->is_busy = 1;

return 0;

@@ -2555,6 +2558,7 @@ void vb2_core_queue_release(struct vb2_queue *q)
__vb2_queue_free(q, vb2_get_num_buffers(q));
kfree(q->bufs);
q->bufs = NULL;
+ q->is_busy = 0;
mutex_unlock(&q->mmap_lock);
}
EXPORT_SYMBOL_GPL(vb2_core_queue_release);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 56719a26a46c..b317286a7b08 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -579,6 +579,7 @@ struct vb2_buf_ops {
* called since poll() needs to return %EPOLLERR in that situation.
* @is_multiplanar: set if buffer type is multiplanar
* @is_output: set if buffer type is output
+ * @is_busy: set if at least one buffer has been allocated at some time.
* @copy_timestamp: set if vb2-core should set timestamps
* @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
* last decoded buffer was already dequeued. Set for capture queues
@@ -644,6 +645,7 @@ struct vb2_queue {
unsigned int waiting_in_dqbuf:1;
unsigned int is_multiplanar:1;
unsigned int is_output:1;
+ unsigned int is_busy:1;
unsigned int copy_timestamp:1;
unsigned int last_buffer_dequeued:1;

@@ -1163,7 +1165,7 @@ static inline unsigned int vb2_get_num_buffers(struct vb2_queue *q)
*/
static inline bool vb2_is_busy(struct vb2_queue *q)
{
- return vb2_get_num_buffers(q) > 0;
+ return !!q->is_busy;
}

/**
--
2.40.1