On Fri, Jan 5, 2024 at 10:40 PM Andrzej Pietrasiewicz
<andrzej.p@xxxxxxxxxxxxx> wrote:
>
> While at it rearrange other comments to match the order of struct members.
>
> Fixes: d65842f7126a ("media: vb2: add waiting_in_dqbuf flag")
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>
> ---
> include/media/videobuf2-core.h | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index e41204df19f0..5020e052eda0 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -72,6 +72,10 @@ struct vb2_buffer;
> * argument to other ops in this structure.
> * @put_userptr: inform the allocator that a USERPTR buffer will no longer
> * be used.
> + * @prepare: called every time the buffer is passed from userspace to the
> + * driver, useful for cache synchronisation, optional.
> + * @finish: called every time the buffer is passed back from the driver
> + * to the userspace, also optional.
> * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
> * used for DMABUF memory types; dev is the alloc device
> * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
> @@ -86,10 +90,6 @@ struct vb2_buffer;
> * dmabuf.
> * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
> * that this driver is done using the dmabuf for now.
> - * @prepare: called every time the buffer is passed from userspace to the
> - * driver, useful for cache synchronisation, optional.
> - * @finish: called every time the buffer is passed back from the driver
> - * to the userspace, also optional.
> * @vaddr: return a kernel virtual address to a given memory buffer
> * associated with the passed private structure or NULL if no
> * such mapping exists.
> @@ -484,7 +484,6 @@ struct vb2_buf_ops {
> * caller. For example, for V4L2, it should match
> * the types defined on &enum v4l2_buf_type.
> * @io_modes: supported io methods (see &enum vb2_io_modes).
> - * @alloc_devs: &struct device memory type/allocator-specific per-plane device
> * @dev: device to use for the default allocation context if the driver
> * doesn't fill in the @alloc_devs array.
> * @dma_attrs: DMA attributes to use for the DMA.
> @@ -550,6 +549,7 @@ struct vb2_buf_ops {
> * @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.
> + * @alloc_devs: &struct device memory type/allocator-specific per-plane device
> */
> /*
> * Private elements (won't appear at the uAPI book):
> @@ -571,6 +571,8 @@ struct vb2_buf_ops {
> * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
> * buffers. Only set for capture queues if qbuf has not yet been
> * called since poll() needs to return %EPOLLERR in that situation.
> + * @waiting_in_dqbuf: set whenever vb2_queue->lock is released while waiting for
> + * a buffer to arrive so that -EBUSY can be returned when appropriate
Appreciate documentation improvements. Thanks!
Just one comment: Could we make it more clear who sets it? For example:
Set by the core for the duration of a blocking DQBUF, when it has
to wait for
a buffer to become available with vb2_queue->lock released. Used to prevent
destroying the queue by other threads.
WDYT?
Best regards,
Tomasz
